UNIVERSITY  OF  CALIFORNIA 
AT  LOS  ANGELES 


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FORTY 

NOTIFIABLE 

DISEASES 

A   SIMPLE    DISCUSSION  OF  THE  MORE 
IMPORTANT  COMMUNICABLE  DISEASES 

BY 

Hiram  Byrd,  B.S.,  M.D, 

Director 

Department  of  Hygiene 

University  of  Alabama 


WORLD  BOOK  COMPANY 

Yonkers-on-Hudson,  New  York* 


19  (|l|l|)  22 


WORLD  BOOK  COMPANY 

THE      HOUSE       OF      APPUEO      KNOWLEDGE 

Established,  1905,  by  Caspar  W.  Hodgson 

Yo^fKERs-oN-HuDsoN,  New  York 
2126  Prairie  Avenue,  Chicago 


Our  knowledge  of  infections  and  how  to 
prevent  them  is  now  so  definite  and  so 
complete  that  in  this  field  of  hygiene  we 
are  able  to  rest  most  of  our  practices  on  a 
sure  basis  of  scientific  truth.  In  conse- 
quence our  victories  over  these  causes  of 
illness  have  been  overwhelming,  and  with 
the  wider  application  of  our  knowledge 
even  more  startling  results  will  be  secured. 
Pubhsher  and  editor  have  pleasure  in 
offering  in  Forty  Notifiable  Diseases  a 
brief  compend  of  important  facts  con- 
cerning communicable  diseases  that  should 
be  a  part  of  the  information  possessed  by 
every  American  citizen.  The  author  is  an 
experienced  and  practical  worker  who 
knows  exactly  where  effort  should  be  di- 
rected to  secure  a  maximum  health  return. 


Copyright,  1922,  by  World  Book  Company 

Copyright  in  Great  Britain 

All  rights  reserved 

PIU^rTBD  IN  II.  9.   A, 


\\^ 

PREFACE 

Hygiene  as  a  subject  of  general  education  has 
taken  on  a  new  importance  since  the  war.  Every 
year  sees  it  introduced  into  more  and  more  colleges 
and  universities,  and  with  equal  pace  it  is  making 
more  and  more  definite  inroads  into  the  curricula 
of  the  secondary  schools. 

But  the  subject  matter  is  still  unformed.  Hardly 
any  two  schools  or  individuals  are  approaching  it 
from  the  same  angle.  This  condition  grows  quite 
naturally  out  of  the  largeness  of  the  subject  and  the 
multiphcity  of  choices  of  material  for  emphasis. 
Out  of  this  situation  comes  the  author's  beUef  that 
the  time  has  arrived  when  we  can  profitably  begin 
the  work  of  standardization. 

Upon  the  theory  that  hygiene  should  ultimately 
eliminate  premature  deaths  and  unnecessary  suffering 
and  at  the  same  time  promote  human  efficiency,  it 
seems  logical  to  direct  our  formative  efforts  toward 
the  points  that  are  most  likely  to  yield  immediate 
returns.^  Those  who  have  studied  the  subject  most  — 
the  health  authorities  —  have,  by  common  consent, 
addressed  themselves  chiefly  to  the  definite  group 
of  diseases  that  forms  the  subject  matter  of  this 
little  book. 

*  In  the  University  of  Alabama  we  devote  one  hour  a  week  for 
one  yeeir  to  hygiene  as  a  required  subject.  Elxperience  has  shown 
that  in  that  time  the  students  can  acquire  a  "thinking  knowledge" 
of  the  notifiable  diseases  and  a  working  knowledge  of  nutrition  emd 
elimination.  That  is  all  we  are  undertaking  to  accomplish  in  this 
course. 

iii 


iv  Preface 

It  might  be  asserted  that  an  adequate  treatment 
of  the  diseases  presupposes  a  working  knowledge  of 
biology  that  is  not  always  available,  even  among 
college  groups.  Yet  it  is  beheved  that  it  is  possible 
to  give  to  those  denied  such  preliminary  preparation 
at  least  a  thorough  grounding  in  the  principal  facts 
connected  with  these  diseases. 

The  idea  behind  the  pubhcation  of  this  book  is, 
then,  to  set  forth  only  those  salient  facts  of  the 
subject  that  the  layman  can  reasonably  be  expected 
to  assimilate,  but  at  the  same  time,  if  possible,  to 
include  all  the  facts  and  ideas  that  are  really  impor- 
tant for  him  to  know  and  to  express  them  in  such 
simple  form  as  to  enable  him  to  begin  to  master 
them  before  college  or  even  high  school  is  reached. 

No  apology  is  offered  for  the  diminutive  size  of 
the  book;  but  if  it  be  challenged  upon  the  ground 
that  the  language  is  too  juvenile  for  grown-ups,  then 
answer  is  made  that  before  beginning  the  work  a 
painstaking  examination  was  made  of  over  2000 
people,  including  college  students  and  professors, 
medical  students,  nurses,  lawyers,  and  teachers,  and 
as  a  result  of  that  examination  the  conclusion  was 
reached  that  there  is  far  graver  danger  of  shooting 
over  the  head  than  under  the  feet. 

H.  B. 


CONTENTS 


Introductory  ..... 

1.  Ahout  Germs    ..... 

2.  The  Forty  Notifiable  Diseases 

3.  Forty  Notifiable  Diseases  Classified  Ac 

CORDING  TO  Cause  .... 

4.  Children's  Diseases 

5.  Sewage  Diseases       .... 

6.  Diseases  Spread  by  Suctorial  Insects 
^7.  The  Venereal  Diseases    . 

8.  Diseases  Affecting  Especially  the  Nerv- 

ous System     ..... 

9.  Diseases  Contracted  from  Lower  Animals 

10.  Diseases  Having  a  Well-defined  Geograph- 

ical Limitation      .... 

11.  Diseases  of  Unknown  Causation 

42.    Some    Diseases    Which    May    Be    Spread 
by  Carriers  .         .  ... 

13.  Diseases  Due  to  Filterable  Viruses 

14.  Nine  Diseases  Amenable  to  Immunization 

15.  Inter-influence  of  Disease 

16.  Tuberculosis    ..... 

17.  The  So-called  Madstone 
Glossary  ...... 


'Tis  his  at  last  who  says  it  best  — 
I'll  try  my  fortune  with  the  rest. 

Lowell 


INTRODUCTORY 

Most  of  the  notifiable  diseases  are  caused  by 
genns  of  one  kind  or  another;  hence,  first  of  all,  the 
chapter  "About  Germs"  should  be  read  carefully 
and  thoughtfully,  and,  if  necessary,  re-read. 

Then  comes  the  Ust  of  "Forty  Notifiable  Dis- 
eases." To  most  persons  the  very  names  of  these 
diseases  look  formidable,  and  instead  of  getting  down 
to  business  and  learning  them,  these  persons  call 
them  "any  old  thing"  and  pass  them  by.  //  should 
be  understood  at  the  outset  that  one  cannot  learn  hygiene 
without  learning  its  language.  Furthermore,  as  soon 
as  one  becomes  serious  about  learning  the  language 
of  hygiene,  the  difficulties  all  fade  away.  It  is  true, 
"poliomyehtis"  is  a  long  word,  but  it  is  not  so  long 
as  "Constantinople,"  and  who  cannot  spell  and 
pronounce  "Constantinople".^  So  many  medical 
terms  are  built  up  from  famihar  components  that  as 
soon  as  the  structure  of  one  of  these  words  is  noted, 
the  meaning  becomes  at  once  apparent.  For  example, 
all  the  "itises"  are  simply  inflammations,  as  inflam- 
mation of  the  appendix,  of  the  bronchi,  of  the  tonsils, 
or  of  the  colon  (lower  bowel);  "hem"  or  "em"  has 
reference  to  blood,  as  anemia  (without  blood),  hyper- 
emia (too  much  blood,  congestion),  /iemorrhage  (a* 
flowing  of  blood),  or  /hematuria  (blood  in  the  urine); 
all  the  "zos"  pertain  to  animals,  as  Zoology;  all  the 
"phytes"  pertain  to  plants,  as  epiphyte  (upon  a 
plant);  the  "hypers"  mean  "over,"  or  too  much, 
as  /hypersensitive,  hypertension;  the  "hypos"  mean 
"under,"    as    /lypodermic    (under    the    skin);    and 

1 


2  Forty  Notifiable  Diseases 

"derma"  means  "the  skin,"  as  epicferm  (upon  the 
skin),  or  cfermaphyte  (a  skin  plant,  of  which  the 
mold-hke  plants  that  cause  "ringworms"  are  good 
examples). 

So  after  reading  the  chapter  "About  Germs,"  it 
is  urged  that  the  names  of  these  "forty  notifiable 
diseases"  be  learned  thoroughly  —  the  speUing,  the 
pronunciation,  and  above  all  the  meaning.  Through- 
out the  course  a  dictionary  may  be  used  to  advantage. 

At  the  head  of  the  list  of  diseases,  the  term  "  Regis- 
tration Area"  is  used.  Stop  and  find  out  what  that 
term  means  before  proceeding  further.  Incidentally 
scan  the  list  and  decide  for  yourself  which  are  the 
most  important  diseases  in  it. 

It  will  be  noted  that  many  of  these  diseases  are 
treated  in  groups.  This  grouping  is  a  teaching  device 
and  is  admittedly  more  or  less  artificial. 

Although  the  language  of  hygiene  is  insisted  on, 
at  the  same  time  technical  terms  have  been  avoided 
in  the  work  as  far  as  possible. 


CHAPTER  ONE 
About  Germs 

There  is  probably  no  word  in  the  English  language 
more  widely  misunderstood  than  the  word  "germ." 
This  wholesale  misunderstanding  clusters  chiefly 
around  four  points  —  the  idea  that  germs  are  uni- 
versally "mean,"  their  size,  their  numbers,  and  the 
way  they  travel. 

A  httle  history  will  help  to  clarify  some  points. 
It  was  Louis  Pasteur  who  started  all  the  talking 
and  writing  about  germs  and  bacteria  and  microbes 
that  has  taken  place  during  the  past  forty  or  fifty 
years.  When,  away  back  in  the  '60's,  a  great  epi- 
demic disease  struck  the  silkworms  of  France  and 
was  playing  greater  havoc  with  the  silkworm  industry 
than  the  boll  weevil  is  with  the  cotton  industry  in 
our  own  country,  Pasteur  took  up  the  disease,  hoping 
to  find  its  cause  and  possibly  how  to  prevent  it. 
He  soon  found  in  the  sick  silkworms  tiny  httle  bodies 
that  were  not  in  the  well  worms.  These  httle  bodies 
were  ahve.  He  found  that  if  some  of  them  were 
put  on  the  food  of  the  well  worms,  these  worms  soon 
got  sick  with  the  same  disease  and  that  the  same 
kind  of  little  bodies  could  then  be  found  in  them. 
In  fine,  he  had  discovered  germs.  This  was  the  first 
time  in  the  world  that  it  was  definitely  proved  that 
httle  living  things  caused  disease. 

It  was  not  long  after  this  that  Koch  discovered 
that  consumption  in  human  beings  was  also  caused 
by  httle  living  things  or  "germs."  Soon  Hansen 
found  that  leprosy  was  caused  by  germs.    Klebs 

3 


4  Forty  Notifiable  Diseases 

proved  that  diphtheria  was  a  germ  disease,  and 
Eberth  found  the  germ  that  caused  typhoid.  By 
this  time  it  was  generally  recognized  that  all  com- 
municable disease  is  caused  by  living  organisms. 

All  these  findings  were  noted  in  the  papers,  and 
people  began  to  read  and  ponder.  At  that  time  a 
"germ"  was  supposed  to  be  about  the  worst  thing 
in  the  world.  Nurses  used  to  frighten  the  babies 
by  telling  them  that  if  they  did  not  hush,  a  "germ" 
would  get  them.  No  one  ever  heard  in  popular 
literature  of  a  good  germ  —  no  one  ever  thought  of 
one  even. 

But  there  are  good  germs,  nevertheless.  They 
outnumber  the  bad  ones  by  far.  They  do  a  great 
deal  more  good  than  the  bad  ones  do  harm.  It  is 
only  through  the  agency  of  "germs"  that  wine  and 
beer  can  be  made.  Wine  and  beer  are  in  bad  repute, 
but  germs  are  still  useful.  All  the  plain  and  fancy 
cheeses  are  made  through  the  agency  of  germs. 
Whenever  you  take  a  vanilla  soda  or  vanilla  ice 
cream,  you  pay  tribute  to  germs,  for  the  vanilla 
bean  has  to  be  fermented  before  the  vanilla  flavor 
is  developed.  In  the  preparation  of  linen,  the  flax 
has  to  undergo  a  process  of  fermentation  called 
"retting." 

But,  more  important  than  all  this,  it  is  now  under- 
stood that  germs  are  of  inestimable  value  to  agri- 
culture. Germs  take  from  the  air  free  nitrogen, 
which  plants  cannot  use,  and  build  it  up  into  nitrates 
that  can  be  used  by  plants;  and  in  turn  animals 
obtain  these  nitrates  by  eating  the  plants.    Then, 


About  Germs  5 

when  these  plants  and  animals  die,  other  germs  tear 
their  bodies  down  and  let  loose  the  nitrogen  once 
again.  Thus  the  air  is  kept  supplied  with  its  full 
amount  of  nitrogen.  Even  the  nitrates  that  leak 
away  into  the  rivers  and  seas  are  attacked  there 
by  germs  that  break  up  these  nitrates  and  release 
their  nitrogen  so  that  it  flows  again  into  the  air. 

This  circle  of  changes  through  which  nitrogen 
passes  is  known  as  the  nitrogen  cycle,  and  were  it 
not  for  the  germs,  the  cycle  would  be  broken.  When 
an  animal  or  plant  died,  instead  of  being  broken 
down  and  its  nitrogen  released  for  further  use  by 
other  plants  and  animals,  it  would  remain  in  a  state 
of  preservation  indefinitely.  The  atmospheric  nitro- 
gen would  be  all  tied  up  in  these  dead  organisms, 
and  the  circulation  of  nitrogen  in  the  world  would 
cease  forever.  So  whenever  you  are  tempted  to 
think  iU  of  a  germ,  remember  that  all  fife  depends 
for  its  existence  on  the  activities  of  these  little  germs. 
Oh,  yes,  there  are  a  few  dozen  harmful  ones,  it  is 
true,  but  there  are  hundreds  that  are  beneficial. 

The  second  great  misunderstanding  about  germs 
concerns  their  size.  The  untrained  find  it  difficult 
to  think  of  anything  as  small  as  a  germ  really  is. 
They  think  to  a  certain  point  in  Uttleness,  and  then 
when  they  try  to  think  of  anything  smaller,  first 
doubt  and  then  increduKty  creeps  in. 

But  reaUy  germs  are  as  small  as  the  bacteriologists 
say  they  are.  For  example,  the  germs  of  tuberculosis, 
which  are  shaped  about  like  corncobs,  are  so  small 
that,  laid  end  to  end,  it  would  take  10,000  to  measure 


6  Forty  Notifiable  Diseases 

an  inch,  and  laid  side  by  side,  it  would  take  80,000 
to  measure  an  inch  I  A  mass  of  tuberculosis  germs 
as  large  as  a  drop  of  water  could  contain  enough 
for  every  man,  woman,  and  child  on  the  face  of  the 
earth  to  have  one  apiece,  and  even  then  some  would 
be  left  over.  A  patient  in  an  advanced  stage  of 
tuberculosis  might  cough  up  and  spit  out  enough 
germs  every  day  to  infect  every  person  in  the  world 
a  thousand  times  over.* 

We  often  speak  of  germs  growing.  We  do  not 
exactly  mean  by  that  that  they  get  larger;  we  mean 
rather  that  they  increase  in  numbers.  They  do  this 
very  rapidly.  As  a  matter  of  fact  they  do  grow  a 
httle  in  size;  but  they  soon  break  in  two,  and  each 
half  becomes  a  new  germ.  In  turn,  each  one  of 
these  new  germs  grows  in  size  a  hltle  and  breaks 
again,  and  so  on.  Under  favorable  conditions  it 
takes  them  only  about  20  minutes  to  grow  a  little 
and  break  in  two.  Suppose  one  were  grown  under 
favorable  conditions,  how  many  would  come  from 
it  in  24  hours .^ 

Starting  at  12.00  o'clock,  we  should  have  1  germ 

a  <'    1  <>  20  «  «  «  « 

«  "  12.40  "  "  "  " 

u  ''I  00  ''  "  "  '* 

u  ''I  20  ''  '^  "  " 

«  «     1 40  «  «  «  « 

M  «       9  QQ  «  «  «  « 

u  u       o  20  u  u  u  u  1 90       u 

u  u     2.40        "         "       "  "  256     " 

'  Thousand  in  this  sense  is  used  only  as  a  fif^ure  of  speech;  it  is 
not  an  overstatement,  but  actually  an  understatement. 


0 

germs 

4 

u 

8 

u 

16 

u 

32 

11 

64 

« 

About  Germs 

Starting  at 

3.00  0 

'clock,  we  should  have 

512  germs 

/      <;              u 

3.20 

u           u        u 

a 

1,024     « 

u              u 

3.40 

u           u        u 

a 

2,048     « 

u             u 

4.00 

u           u         a 

a 

4,096     « 

u             u 

4.20 

u           u         u 

u 

8,192     « 

«  «    4.40        «        «       «  «     16,384     " 

A.  Fischer  has  completed  the  calculation  for  the 
24-hoiir  period  and  states  that  at  the  end  of  this 
period  there  would  be  1600  trillion  new  germs!  But 
it  is  only  when  they  have  the  right  kind  of  nutrition 
and  environment  that  they  multiply  at  such  a  rate  — 
or  at  all,  for  that  matter. 

A  knowledge  of  their  smallness  and  numbers  paves 
the  way  for  an  understanding  of  their  methods  of 
travel.  You  know  how  easily  coal  dust  sticks  to  a 
person's  skin  or  to  clothes.  You  know  also  how  dirt 
rubs  off  and  soils  other  things  with  which  it  comes 
in  contact,  and  how  such  dirt  is  thus  carried  from  place 
to  place.  That  is  about  the  way  germs  travel  —  not 
such  aristocratic  germs  as  malarial  parasites,  that 
travel  by  "flying  machines,"  as  we  shall  learn  later, 
but  the  common  germs  of  tuberculosis  or  diphtheria, 
which  have  to  get  around  in  the  best  way  they  can. 

Germs  may  be  either  small  plants  or  small  animals. 
The  ones  most  commonly  met  with  are  Uttle  plants 
that  are  called  bacteria  (singular,  bacterium).  The 
simplest  and  most  common  form  encountered  among 
these  is  the  spherical.  A  spherical  bacterium  is  called 
a  coccus  (plural,  cocci). 

In  reproducing,  a  coccus  grows  a  tiny  bit  and  then 
splits  in  half.    Sometimes  these  two  halves  do  not 


8  Forty  Notifiable  Diseases 

separate  entirely  but  cling  together,  giving  the 
appearance  of  two  cocci  fastened  tightly  to  each 
other.  Groups  of  cocci  arranged  hke  tliis  are  called 
diplococci.  Three  of  our  forty  diseases  are  caused 
by  diplococci;  namely,  meningitis,  gonorrhea,  and 
pneumonia. 

Sometimes  the  cocci,  instead  of  arranging  them- 
selves in  twos,  arrange  themselves  in  a  long  chain, 
like  a  string  of  beads.  This  arrangement  of  cocci  is 
called  streptococci.  None  of  our  notifiable  diseases 
are  known  to  be  caused  by  streptococci,  but  ery- 
sipelas and  puerperal  (childbed  fever)  are  caused 
by  this  group  of  cocci.  Occasionally  streptococci 
also  attack  the  throat,  causing  distressing  symptoms. 

Sometimes  the  cocci  arrange  themselves  in  clusters 
like  a  bunch  of  grapes.  Grouped  thus,  they  are 
called  staphylococci.  It  is  the  germs  of  this  group 
that  commonly  cause  boils. 

Others  of  these  vegetable  germs,  instead  of  being 
round,  are  rod-shaped,  something  like  a  corncob. 
Such  germs  are  called  bacilli  (singular,  bacillus). 
The  germs  of  tuberculosis,  typhoid,  paratyphoid, 
bacillary  dysentery,  glanders,  and  leprosy  are  all 
bacilli.  The  bacilli  of  anthrax  often  arrange  them- 
selves in  chains,  called  slreptobacilli. 

Besides  the  round  and  the  rod-shaped  germs  there 
is  still  another  group,  composed  of  those  having  a 
spiral  or  corkscrew  shape.  These  are  collectively 
known  as  spirilla  (singular,  spirillum).  The  germ 
of  Asiatic  cholera  belongs  to  this  group. 


CHAPTER  TWO 
The  Forty  ^  Notifiable  Diseases 

In  the  table  on  page  11  the  forty  notifiable  dis- 
eases which  we  are  to  study  in  detail  are  arranged 
in  the  order  of  the  number  of  deaths  caused  by  each 
in  the  Registration  Area  of  the  United  States  in 
1917,  paralleled  with  the  number  of  deaths  from 
the  same  diseases  in  the  great  epidemic  year  of  1918. 

The  Death  Registration  Area  of  the  United  States 
(exclusive  of  Hawaii)  consists  of  34  states,  the  Dis- 
trict of  Columbia,  and  16  cities  in  the  non-registra- 
tion states.  The  14  states  not  in  the  Registration 
Area  are: 


Alabama 

Iowa 

South  Dakota 

Arizona 

Nevada 

Texas 

Arkansas 

New  Mexico 

West  Virginia 

Georgia 

North  Dakota 

Wyoming 

Idaho 

Oklahoma 

A  state  or  city  is  admitted  to  the  Registration  Area 
whenever  it  makes  provision  for  reporting  accurately 
90  per  cent  or  more  of  all  deaths  occurring  within 
its  bounds. 

The  Birth  Registration  Area  is  not  quite  so  large 
as  the  Registration  Area  for  deaths,  and  includes 
only  those  states  (not  cities)  that  are  reporting  90 
per  cent  of  all  births  occurring  within  their  bounds. 
In  1919  it  consisted  of  22  states  and  the  District  of 
Columbia,  as  follows: 

^  "Forty"  is  not  to  be  taken  literally.  The  actual  number  of 
notifiable  diseases  varies  from  state  to  state.  Besides,  this  does  not 
include  industrial  diseases  that  are,  in  many  states,  notifiable. 

9 


10 


Forty  Notifiable  Diseases 


California 

Connecticut 

District  of  Columbia 

Indiana 

Kansas 

Kentucky 

Maine 

Maryland 


Massachusetts 
Michigan 
Minnesota 
New  Hampshire 
New  York 
North  Carolina 
Ohio 
Oregon 


Pennsylvania 

South  Carolina 

Utah 

Vermont 

Virginia 

Washington 

Wisconsin 


This  area  embraces  58.6  per  cent  of  the  estimated 
population  of  the  United  States. 


Table  1 


Disease 

Tuberculosis  (all  forms) 

Pneumonia 

Cancer 

Influenza 

Diphtheria   (together  with  croup  and  septic 

sore  throat) 

Measles 

Typhoid  (including  also  paratyphoid)  .... 

Whooping-cough 

Syphilis •. 

Meningitis      

Dysentery  (amebic,  bacillary,  and  others)    .    . 

Pellagra 

Scarlet  fever 

Malaria 

Tetanus  (lockjaw) 

EjQcephalitis 

Gonorrhea 

Cholera  nostras 

Smallpox 

Rabies  (hydrophobia) 

Anthrax 

Mycoses  (actinomycosis  and  others)      .... 

Hookworm  disease 

Leprosy 

Typhus 

Glanders 

Chancroid  (not  fatal) 

Chicken  pox  (not  fatal) 

Asiatic  cholera  (no  cases) 

Dengue  (not  fatsd) 

Favus  (not  fatal) 

German  measles  (not  fatal) 

Bubonic  plague  (no  cases) 

Poliomyelitis    (infantile  paralysis)  (sometimes 

fatal) 

Rocky    Moimtain   spotted   fever   (sometimes 

fatal) 

Trachoma  (not  fatal) 

Trichinosis  (rarely  fatal)      

Yellow  fever  (no  cases) 

Mumps  (not  fatal) 

11 


Deaths 

Deaths 

1917 

1918 

110,144 

121,204 

74,517 

167,703 

61,429 

65,282 

12,965 

234,290 

12,442 

11,183 

10,442 

8,223 

10,089 

10,167 

7,837 

13,728 

7,795 

7,522 

6,673 

7,500 

4,546 

4,720 

3,666 

3,711 

3,124 

2,335 

2,385 

2,534 

1,329 

1,276 

620 

687 

595 

500 

242 

299 

204 

248 

66 

63 

61 

34 

39 

46 

29 

28 

17 

24 

16 

3 

4 

4 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

CHAPTER  THREE 


Forty  Notifiable  Diseases  Classified 
According  to  Cause 

In  the  table  below  the  forty  notifiable  diseases 
have  been  arranged  in  convenient  form  for  ready 
reference  and  comparison  as  to  their  general  causes. 

Table  2 


8. 

9. 

10. 


11. 
12. 

n. 

14. 
15. 


Actinomyco-sis 
Anthrax     .    . 
Cancer*  .    .    . 
Chancroid 
Chicken  pox 


Cholera 

Asiatic    .    .    . 

Nostras  .    .    . 
Continued    fever 

entity)  .  . 
Dengue  .... 
Diphtheria  .  . 
Dysentery 

Amebic  .    .    . 

Bacillary    .    . 


(not    a    disea.se 


Encephalitis  (lethargic) 

Favus     

CJerman  measles   .    .    . 

(Ilanders 

fionorrhea 


< 

< 

z 
is 

o 

H 

z 

Is 

>  a 

z  « 

o 

z  ^ 

^^ 

^ 

^ 

o 

s 

0 

K 

z 

X 

u 

uj 

U 

X 

X 

X 
X 

X 

X 
X 

X 

X 

X 

X 

X 

X 

X 

X 

'  S<'e  page  47.  '  Presumably  not  caused  by  germs. 

12 


Diseases  Classified  According  to  Cause 

Table  2  (Continued) 


13 


16.  Hookworms 

17.  Influenza    

18.  Leprosy .    .    . 

19.  Malaria      

20.  Measles      

21.  Meningitis  (cerebrospinal  fever) 

22.  Mumps 

23.  Paratyphoid 

24.  PeUagra^ 

25.  Plague    

26.  Pneumonia 

27.  Poliomyelitis 

28.  Rabies 

29.  Rocky  Mountain  spotted  fever 

30.  Scarlet  fever 

31.  Smallpox 

32.  Syphilis      

33.  Tetanus 

34.  Trachoma      

35.  Trichinosis 

36.  Tuberculosis 

37.  Typhoid 

38.  Typhus 

39.  Whooping-cough 

40.  Yellow  fever 


s 


H 

H  cs 

o 

z 

i4 


X 
X 


X 

? 

X 


X 
X 


X 
X 

X? 


X 
X 


o 

H 

O 


o 


X 
X 
X 

X 
X 


X 

3 


^See  page  47. 


*  Presumably  not  caused  by  germs. 


CHAPTER  FOUR 

Children's  Diseases 

Chicken  pox  Scarlet  fever 

German  measles  Whooping-coiigh^ 

Measles  Smallpox 

Five  of  the  six  foregoing  diseases  are  commonly 
known  as  children's  diseases,  but  smallpox  has  so 
many  points  in  common  with  the  others  that  it  is 
included. 

Chicken  pox  and  German  measles  rarely,  if  ever, 
cause  a  death  and  would  not  be  included  among 
the  notifiable  diseases  but  for  the  reason  that  through 
mistaken  diagnosis  epidemics  of  smallpox  and  mea- 
sles may  get  started. 

Measles,  scarlet  fever,  and  whooping-cough  are 
really  serious  diseases  among  children.  By  reference 
to  Table  1  it  will  be  seen  that  in  1917  in  the  Regis- 
tration Area  measles  caused  over  10,000  deaths, 
while  whooping-cough  caused  over  7000  and  scarlet 
fever  over  3000. 

Children  should  never  be  rushed  into  these  diseases 
to  get  them  and  ''have  it  over^ 

Smallpox,  although  it  has  been  in  the  history  of 
the  world  a  great  scourge,  has  been  "vaccinated  to 
death,"  so  that  at  present  it  is  of  little  consequence, 
causing  only  one  fiftieth  as  many  deaths  as  measles. 

'  In  1906  Bordet  and  Gengou  isolated  what  they  thought  was 
the  germ  of  whooping-cough,  but  their  claims  have  not  been  univer- 
sally arx^pted.  On  the  theory  that  this  germ  is  the  cause  of  whooping- 
4-uiigh,  a  corresponding  vaccine  against  the  disease  has  been  placed 
on  the  market,  but  it  cannot  lie  said  to  be  beyond  the  experinienlul 
stage. 

14 


Children  s  Diseases  15 

The  members  of  this  group  have  many  points  in 
common:  they  are  all  contagious;  the  cause  of  each 
is  unknown;  all  date  to  a  definite  exposure,  followed 
by  an  incubation  period,  and  then  a  rather  sudden 
onset  (except  in  the  case  of  whooping-cough,  which 
begins  more  gradually);  all  cause  more  or  less  rise 
of  temperature  and  a  quickening  of  the  pulse;  all 
are  self-hmited  (that  is,  the  patients  get  well  or  die, 
as  the  case  may  be,  within  a  fairly  definite  period) ; 
all  leave  the  individual  immune;  all  have  an  erup- 
tion, except  whooping-cough;  and  all  are  managed 
alike,  except  smallpox,  which,  being  the  one  member 
of  the  group  against  which  we  can  vaccinate,  is  in 
consequence  the  one  member  that  is  most  perfectly 
controllable. 

It  has  been  customary  time  out  of  mind  to  try 
to  control  these  diseases  by  quarantine,  but  so  many 
mild  cases  occur,  that  are  never  reported  to  the 
health  authorities  and  accordingly  escape  quarantine 
restrictions,  that  quarantine  methods  are  only  in 
part  effective.  Smallpox  can  be  effectively  controlled 
by  vaccination  of  those  exposed  or  likely  to  be 
exposed. 


CHAPTER  FIVE 

Sewage  Diseases 

Typhoid  fever  ^  Bacillary  dysentery 

Paratyphoid  fever  Amebic  dysentery 

Asiatic  cholera  Hookworm  disease 

The  first  four  of  these  six  diseases  —  typhoid  fever, 
paratyphoid  fever,  Asiatic  cholera,  and  bacillary 
dysentery  —  are  due  to  well-known  vegetable  germs; 
of  the  last  two,  one  —  amebic  dysentery  —  is  caused 
by  a  minute  animal  organism,  the  ameba,  and  the 
other  by  a  worm,  the  hookworm. 

These  six  diseases  have  three  important  points  in 
common:  (1)  they  are  all  due  to  living  organisms; 
(2)  the  chief  locus  of  the  trouble  is  in  the  intestinal 
tract;  and  (3)  the  chief  desideratum  in  all  is  their 
prevention  through  proper  sewage  disposal. 

In  studying  this  group  of  diseases  the  first  thing 
to  determine  is  how  the  germs  get  from  the  alimen- 
tary tract  of  the  sick  to  the  alimentary  tract  of  the 
well  and  thereby  spread  the  disease.  In  amebic 
dysentery,  which  will  be  considered  first,  the  way  is 
not  devious,  but  very  direct.  The  amebae  (little 
animals  too  small  to  be  seen  with  the  naked  eye) 
are  excreted  in  the  stools.  A  person  with  amebic 
dysentery  is  giving  them  off  literally  by  the  millions. 
Now  whenever  these  amebic  stools  find  their  way 
into  drinking-water  and  are  swallowed,  the  deed  is 
accomplished.  This  seems  to  be  the  only  way  amebic 
dysentery  is  ordinarily  spread.    It  is  not  spread  by 

'  Entirely  different  from  typhus  fever. 
16 


Sewage  Diseases  17 

flies  as  is  the  typhoid  germ  or  that  of  bacillary  dysen- 
tery; and  ordinarily  it  has  no  way  of  contaminating 
milk.  One  can  imagine  it  contaminating  oysters  and 
running  the  gantlet  that  way. 

An  epidemic  of  one  of  these  diseases  that  once 
occmred  at  Tampa,  Florida,  was  caused  in  an  un- 
usual manner.  The  vegetable  gardens  at  Ybor  City, 
a  suburb  of  Tampa,  were  flooded  during  the  heavy 
rains.  Soon  after  the  rains  subsided,  lettuce  came 
into  the  market  (lettuce,  it  will  be  remembered,  is 
usually  eaten  raw).  Following  this  incident  there 
occurred  in  Tampa  an  epidemic  of  typhoid  fever 
and  a  considerable  increase  of  amebic  dysentery. 
However,  accidents  of  this  kind  are  rare,  and  in 
pubhc  health  practice  it  is  customary  to  consider 
any  appreciable  increase  in  the  prevalence  of  amebic 
dysentery  as  proof  of  sewage  contamination  of  the 
community  drinking-water. 

The  amebae  of  dysentery  leave  the  body  of  the 
sick  person  only  in  the  stools;  but  the  germs  of  some 
of  the  other  diseases  (e.g.,  of  typhoid  and  para- 
typhoid), besides  leaving  it  in  the  stools  sometimes 
leave  it  in  the  urine  also,  and  occasionally  they 
escape  in  the  saliva  (as  in  typhoid,  for  example). 
This  multiplies  opportunities  for  spreading  these 
diseases.  Indeed,  the  chances  of  infection  through 
contaminated  drinking-water  are  so  great  that  some- 
times we  have  great  water-borne  epidemics,  par- 
ticularly of  Asiatic  cholera;  whereas  the  prevalence 
of  amebic  dysentery  can  hardly  ever  be  said  to  reach 
epidemic  proportions.    Then  there  are  other  ways 


18  Forty  Notifiable  Diseases 

of  spreading  these  diseases.  A  person  in  attendance 
upon  a  case  of  typhoid  fever,  say,  will  get  the  infection 
on  his  hands.  Soon  the  hands  go  to  the  mouth  and 
some  of  the  germs  are  left  there.  This  method  of 
transmitting  the  disease  is  known  as  finger  infection. 
Finger  infection  is  common  where  the  patient  is 
cared  for  by  untrained  help.  Sometimes,  even  now, 
typhoid  fever  goes  nearly  through  a  family  by  finger 
infection. 

But  finger  infection  is  only  one  way  by  which  the 
typhoid  bacilli  get  from  the  intestine  of  the  sick  to 
the  intestine  of  the  well.  There  are  other  ways. 
Suppose  the  stools  from  one  of  these  patients  are 
thrown  out  in  the  open.  Flies  are  soon  attracted  to 
them.  The  flies  feed  on  them,  at  the  same  time 
walking  over  them  and  getting  the  germs  on  their 
feet.  Then  they  fly  to  the  house,  into  the  dining 
room,  and  walk  over  the  food.  If  we  had  eyes  a 
thousand  times  as  fine  as  we  have,  we  could  see, 
wherever  a  fly  walks  after  coming  from  one  of  these 
open  privies,  a  trail  of  germs  like  mud  tracks  on  a 
clean  floor.  An  experimenter  once  let  a  fly  walk 
across  a  plate  of  sterile  gelatin.  The  germs  that  it 
left  in  its  tracks  grew  and  multiplied,  and  by  the 
next  day  they  were  so  numerous  that  they  could 
be  seen  with  the  naked  eye.  There  were  little  masses 
of  germs  wherever  the  fly  had  put  its  foot  down. 
When  flies  carry  the  germs  from  typhoid  stools  to 
food,  the  method  of  transmission  is  called  Jly  in- 
jection. 

Again,  when  a  person  gets  well  from  typhoid,  he 


Sewage  Diseases  19 

may  still  excrete  the  germs  for  weeks  or  months,  or 
even  years  afterward.  In  this  case  he  is  known  as  a 
typhoid  carrier.  Typhoid  carriers  spread  the  germs  in 
their  wake  and  are  often  the  means  of  spreading  the 
disease.  This  is  particularly  true  when  the  carrier 
happens  to  be  engaged  as  a  milker  or  cook. 

There  was  once  a  famous  typhoid  carrier  in  New 
York,  known  as  "Typhoid  Mary."  She  was  a  cook, 
and  wherever  she  took  service  the  family  sooner  or 
later  developed  typhoid  fever.  Sixty-seven  cases  of 
the  disease  were  traced  to  this  one  cook. 

You  have  doubtless  heard  of  typhoid  from  milk. 
About  the  only  way  we  get  typhoid  from  milk  is 
through  the  agency  of  a  typhoid  carrier  engaged 
as  a  milker.  A  number  of  epidemics  have  been  traced 
to  this  cause.  But  today  in  well-managed  dairies  all 
milkers  are  examined  to  make  sure  that  they  are 
not  typhoid  carriers. 

Now  all  that  has  been  said  about  typhoid  may 
be  said  also,  with  perhaps  a  little  less  emphasis, 
about  paratyphoid,  Asiatic  cholera,  and  bacillary 
dysentery. 

This  disposes,  then,  of  five  of  the  six  sewage  dis-  / 
eases.  It  has  been  seen  that  the  amebae  leave  the 
body  only  in  the  stools,  and  that  they  find  their 
way  into  the  bodies  of  others  only  through  con- 
taminated drinking-water.  The  germs  of  typhoid, 
paratyphoid,  Asiatic  cholera,  and  bacillary  dysentery 
leave  the  body  through  the  stools,  and  sometimes, 
as  in  typhoid,  through  the  urine  and  saliva.  They 
find  their  way  to  the  mouths  of  others  not  only 


20  Forty  Notifiable  Diseases 

through  drinking-water,  but  by  fingers,  flies,  and 
food  (milk  in  particular).  It  now  remains  to  see 
how  the  hookworms  get  from  one  person  to  another. 

Unlike  the  amebae  and  the  typhoid  germs,  the 
hookworms  do  not  leave  the  human  body  to  get 
to  other  people;  they  just  send  their  eggs.  The  worms 
remain  in  the  intestine,  feeding  and  laying  eggs. 
Now  the  eggs  —  and  this  is  an  important  point  —  do 
not  hatch  in  the  intestine.  They  must  pass  out  in  the 
stools  and  get  to  the  air  before  hatching  will  take 
place.  When  a  child  has  hookworms,  his  stools  are 
loaded  with  eggs.  These  eggs  are  too  small  to  be 
seen  with  the  naked  eye,  but  they  can  be  seen  under 
a  microscope  and  in  that  way  the  doctor  can  deter- 
mine if  a  child  has  hookworms  —  by  finding  the 
eggs.  Let  us  follow  these  eggs  after  they  have  passed 
out  in  the  stools.  If  the  stools  are  passed  into  a 
sewer,  the  eggs  go  out  into  the  river,  or  wherever 
the  sewer  empties,  and  are  devoured  by  the  tiny 
animals  that  together  with  tiny  plants  go  to  make 
up  the  plankton;  or  if  they  are  not  thus  destroyed, 
they  disintegrate  —  they  never  hatch. 

On  the  other  hand,  suppose  the  sIjooU  are  deposited 
on  the  ground  in  a  shady  damp  place,  as  along  a 
watercourse.  Here  they  find  ideal  conditions  and 
soon  hatch.  These  eggs,  bear  in  mind,  are  so  small 
that  it  takes  a  microscope  to  see  them;  and  the  worm 
that  hatches  out  is  also  microscopic  in  size.  They 
can  live  in  this  damp  soil  for  a  long  lime.  They 
even  grow  a  little  and  moult,  and  then  look  as  if 
they  were  going  to  moult  again;  that  is,  they  seem 


Sewage  Diseases  21 

to  get  loose  from  their  outside  skin,  but  they  stay 
inside  of  it,  so  that  they  look  like  little  wiggly  cap- 
sules.  In  this  condition  they  are  ready  for  business. 

Their  business  is  to  get  into  the  intestine  of  a 
child. ^  They  cannot  go  out  and  hunt  a  child,  they 
just  have  to  wait  and  chance  one  coming  along. 
Myriads  of  them  die  while  waiting.  But  occasionally 
the  child  comes  along  and  they  make  connection. 
He  must  be  barefoot  or  have  holes  in  his  shoes,  for 
the  little  worms  cannot  get  through  leather.  But 
let  us  suppose  that  one  of  these  worms  has  been 
able  to  come  in  contact  with  the  child's  bare  foot. 
This  worm,  capsule  and  all,  wiggles  his  way  into 
the  pores  of  the  skin  (the  pores,  it  should  be  under- 
stood, do  not  go  all  the  way  through  the  skin). 
When  the  worm  comes  to  the  end  of  the  little  hole 
or  pore  which  he  has  entered,  he  pushes  through 
his  capsule  and  goes  right  on  through  the  remainder 
of  the  skin  and  on  into  the  foot  of  the  child.  The 
capsule  he  leaves  behind,  in  the  skin.  It  is  probably 
this  capsule  or  outer  skin  of  the  young  hookworm, 
left  in  the  skin  of  the  child,  that  causes  the  itching 
known  as  "ground  itch."  We  shall  not  stop  to  discuss 
the  ground  itch  now,  but  shall  follow  up  the  httle 
worm's  journey. 

When  he  gets  through  the  skin  of  the  child's  foot, 
he  gets  into  the  blood  vessels.  Here  he  finds  himself 
in  the  blood  stream,  and  traveling  becomes  easier. 

*  In  this  country  children  are  the  chief  sufferers  from  hookworm 
disease,  but  adults  are  also  susceptible  and  in  some  countries  the 
disease  is  widespread  among  the  adult  population. 


22  Forty  Notifiable  Diseases 

He  is  just  carried  along  with  the  current  of  blood, 
and  on  he  goes.  This  blood  stream  is  very,  very 
small  at  first,  but  gets  larger  as  other  vessels  join  it, 
and  as  it  approaches  the  heart  it  is  as  large  as  one's 
little  finger.  After  the  worm  has  gone  through  the 
heart  and  has  come  out  on  the  other  side,  he  goes 
strmght  toward  the  lungs.  Then  the  vessels  get 
smaller  and  smaller,  and  about  the  time  he  gets  to 
the  lungs  he  is  so  cramped  that  he  cannot  go  any 
farther  and  cannot  even  turn  over  in  the  little  blood 
vessel.  He  is  now  in  the  capillaries  of  the  lungs. 
These  little  capillaries  have  such  thin  walls  that 
the  oxygen  we  breathe  just  goes  through  the  capillary 
walls  into  the  blood,  and  the  carbon  dioxid  goes 
through  the  same  thin  walls  the  other  way  to  be 
thrown  off.  The  little  worm  is  now  at  one  of  the 
most  interesting  places  in  the  body.  If  he  could 
only  understand  things  at  this  juncture!  Thousands 
of  millions  of  little  red  blood  corpuscles  are  all  around 
him,  each  acting  as  if  it  were  a  thing  alive,  and  busy 
laying  off  its  cargo  of  carbon  dioxid  and  taking  on 
a  cargo  of  oxygen  for  remote  parts  of  the  body. 
But  the  little  worm  does  not  tarry  here  long.  There 
is  nothing  between  him  and  the  outside  air  in  the 
lungs  but  the  thin  membrane,  and  he  soon  breaks 
through  that  and  finds  himself  in  the  air  spaces  of 
the  lungs. 

In  the  lungs  the  little  worm  is  a  foreign  body, 
and  a  foreign  body  in  the  lungs  causes  coughing. 
So  the  child  coughs;  gradually  the  worm  is  raised 
till  he  gets  to  the  throat  and  is  swallowed.    Now  he 


Sewage  Diseases  23 

goes  straight  into  the  stomach,  and  then  on  through 
it,  into  the  intestine.  How  he  gets  through  the 
stomach  without  being  digested  hke  any  other  tiny 
piece  of  meat  is  more  than  I  can  tell,  but  he  seems 
to  do  it  —  at  any  rate  he  finally  stops  in  the  intestine, 
where  he  attaches  himself  to  the  lining  and  begins 
to  suck  like  a  baby  possum.  You  know  that  when 
a  possum  is  born,  it  is  very,  very  small.  Its 
mother  puts  it  into  the  pouch  and  attaches  its  mouth 
to  a  httle  nipple  found  there.  The  httle  possum 
remains  attached  to  that  nipple  through  thick  and 
thin,  sucking  when  hungry,  and  growing  and  growing 
until  it  is  too  large  for  the  pouch.  That  is  the  very 
way  the  baby  hookworm  does.  You  should  know 
that  in  the  intestines  are  thousands  of  little  nipples 
called  villi.  The  baby  hookworm  seizes  a  group  of 
these  and  goes  to  sucking;  but  he  does  not  get  milk 
— he  gets  blood.  On  this  food  the  young  hookworms 
grow  until  they  are  full-grown  hookworms. 

That  is  the  life  history,  or  the  circuit,  of  the  hook- 
worm. It  begins  in  the  intestine  of  one  child  and 
ends  in  that  of  another.  It  takes  about  six  weeks 
from  the  time  the  child  has  ground  itch  until  the 
young  worms  reach  the  intestine,  grow  up,  and  begin 
to  lay  eggs  themselves. 

The  ground-itch  route  is  the  chief  method  of 
spread  of  hookworm  infection,  but  it  has  been  shown 
that  young  hookworms  may  live  for  some  time  on 
vegetables,  and  it  seems  certain  that  the  infection 
may  be  acquired  through  eating  such  infected 
vegetables  raw.    This  would  explain  how  it  is  that 


r 


24  Forty  Notifiable  Diseases 

adulls,  whose  feel  are  prolecled  by  shoes,  sometimes 
become  infected. 

This  completes  our  discussion  of  the  sewage-borne 
diseases.  Summing  up:  first,  we  have  amebic  dysen- 
tery, strictly  water-borne;  next,  the  vegetable  group 
—  composed  of  typhoid,  paratyphoid,  Asiatic  cholera, 
and  bacillary  dysentery  —  which  are  transmitted 
through  water,  and  also  by  flies,  fingers,  and  food; 
and  last,  the  hookworm,  which  generally  travels  by 
the  ground-itch  route,  less  commonly  by  infected 
vegetables.  From  these  facts  it  is  clear  that  every 
one  of  these  six  diseases  would  disappear  from  the 
face  of  the  earth  if  all  sewage  were  properly  disposed 
of.  Perhaps  the  world's  greatest  sanitary  problem 
today  is  the  disposal  of  human  excrement.  Victor 
Heiser  has  estimated  that  even  today  there  are  100 
million  people  in  the  world  perennially  sick  from  im- 
proper methods  of  sewage  disposal,  although  its 
dangers  have  been  known  since  the  time  of  Moses, 
some  thousands  of  years  ago. 


CHAPTER  SIX 
Diseases  Spread  by  Suctorial  Insects 

Dengue  Plague 

Malaria  Typhus  fever 

Yellow  fever  Rocky  Mountain  spotted  fever 

Of  the  forty  diseases  under  discussion,  parasites 
of  six  (those  listed  above)  manage  to  get  from  host 
to  host  through  the  aid  of  other  parasites.  Each 
of  these  disease-producing  pairs  of  parasites  has  a 
system  of  teamwork  which  is  hard  to  break  up. 
The  parasites  causing  dengue,  malaria,  and  yellow 
fever  have  mosquitoes  as  partners  in  their  iniquity; 
the  parasite  causing  plague  is  carried  from  rat  to 
rat  and  from  rat  to  man  by  fleas;  the  typhus-fever 
parasite  is  a  "buddy"  of  the  head  and  body  hce; 
and  the  parasites  of  the  Rocky  Mountain  spotted 
fever  chum  with  the  lowly  tick. 

The  malarial  parasites  were  discovered  about  forty 
years  ago.  They  are  now  so  well  known  that  they 
have  even  been  separated  into  different  species,  at 
least  three  of  which  are  recognized  by  biologists. 
The  plague  parasite  has  been  known  since  1894, 
but  the  yellow-fever  parasite  was  not  discovered 
until  three  years  ago.  The  germs  of  the  remaining 
three  —  dengue,  typhus  fever,  and  Rocky  Mountain 
spotted  fever — are  still  in  hiding,  although  the 
Typhus  Research  Commission  of  the  League  of  Red 
Cross  Societies  to  Poland  reports  substantial  progress 
in  investigating  the  cause  of  typhus.^ 

^See  Journal  of  the  American  Medical  Association,  page  1054, 
April  8,  1922. 

25 


26  Forty  Notifiable  Diseases 

The  parasite  of  plague  is  a  vegetable  organism, 
a  bacillus;  the  parasite  of  malaria  is  an  animal  organ- 
ism; and  the  parasite  of  yellow  fever,  according  to  its 
discoverer,  Noguchi,  may  be  described  as  "betwixt 
and  between"  a  vegetable  and  an  animal.  The  para- 
sites of  dengue,  typhus  fever,  and  Rocky  Mountain 
spotted  fever  are,  as  above  indicated,  unknown. 

The  malarial  parasites  are  transmitted  by  mos- 
quitoes of  the  genus  Anopheles;  and  both  the  yellow 
fever  and  the  dengue  parasites  are  transmitted  by 
the  species  of  mosquito  known  as  /Edes  calopus. 
There  are  some  50  different  species  of  Anopheles 
known.  However,  not  all  of  them  transmit  malaria. 
The  y^des  calopus  is  the  same  mosquito  that  we 
used  to  call  the  Stegomyia  calopus,  and  before  that 
we  called  him^  the  Stegomyia  fasciala,  and  still  before 
that,  at  the  time  Walter  Reed  caught  him  red-handed 
in  the  act  of  transmitting  yellow  fever,  he  was  the 
Culex  fasciala.  In  fact,  if  you  were  to  chase  him 
back  through  all  his  names,  you  would  find  he  has 
been  christened  no  fewer  than  seventeen  or  eighteen 
times.  Such  a  wholesale  renaming  process  usually 
comes  about  through  the  fact  that  from  time  to 
time  different  persons  in  different  parts  of  the  world 
describe  and  name  a  species,  and  later  it  is  found 
that  these  names  all  mean  the  same  thing;  then, 
by  agreement,  the  oldest  name  sticks. 

('onsidering  the  malarial  parasite  a  little  more  in 
detail,  it  will  be  noted  that  tlie  mosquito  is  host 

'  In  j>eraonifying  lliR  niosquiU),  the  masculine  pronoun  is  u.srd 
here,  ulthough  it  should  be  undersUxxl  that  it  is  really  the  female 
that  actually  trantinuts  the  disease;  the  male  never  bites  a  f>erson. 


Diseases  Spread  by  Insects  27 

for  this  parasite,  and  that  the  human  being  is  host 
for  both  the  malarial  parasite  and  the  mosquito. 

The  malarial  parasite  reproduces  in  the  blood  of 
the  human  being;  it  also  reproduces  in  the  body 
of  the  mosquito.  In  the  hmnan  being  it  reproduces 
without  sex,  but  in  the  mosquito  there  is  a  mating 
process;  that  is,  the  reproduction  is  sexual.  The 
host  in  which  sexual  reproduction  takes  place  is 
known  as  the  definitive  host,  and  the  one  in  which 
non-sexual  reproduction  takes  place  is  known  as 
the  intermediate  host.  Accordingly,  the  human  being 
is  the  intermediate  host  and  the  mosquito  the  defini- 
tive host  for  the  malarial  parasite. 

In  theory  it  is  possible  to  control  any  of  these 
team-work  diseases  by  breaking  up  the  team;  that 
is,  by  controlling  either  member  of  it  —  the  malarial 
parasite  or  the  mosquito;  the  plague  bacillus,  the 
rat,  or  the  flea;  the  typhus  germ  or  the  louse. 

In  practice  we  sometimes  attack  in  one  place 
and  sometimes  in  another.  We  may  try  to  break 
up  the  germ-mosquito  combination  by  kiUing  the 
germ  or  by  kiUing  the  mosquito.  When  we  try  to 
control  malaria  by  the  broadcast  use  of  quinine,  as 
is  being  done  in  an  experiment  in  Sunflower  County, 
Mississippi,  we  are  making  our  attack  on  the  germ. 
When  we  try  to  control  it  by  drainage  or  oiHng, 
we  are  attacking  the  mosquito. 

In  combating  plague,  it  has  been  found  most 
practicable  to  attack  the  germ-flea-rat  combine  by 
kiUing  the  rat.  That  is  why  an  anti-plague  cam- 
paign consists  of  rat  kilKng. 


28  Forty  Notifiable  Diseases 

In  typhus  fever,  the  gerra-louse  combine  is  broken 
up  by  killing  the  louse  —  "delousing,"  as  the  process 
is  called. 

In  dengue  and  yellow  fever  the  attack  is  made 
on  the  mosquito. 

Rocky  Mountain  spotted  fever,  as  above  indicated, 
is  transmitted  by  the  tick,'  Dermacentor  andersoni. 

Back  in  1906  Ricketts  discovered  how  this  fever 
is  transmitted.  Not  only  adult  ticks,  both  male  and 
female,  but  also  larvae  and  nymphs,  are  capable  of 
transmitting  the  disease,  and  the  eggs  from  infected 
ticks  in  turn  hatch  out  infected  larvae. 

The  natural  reservoir  of  the  infection  seems  to 
be  the  wild  animals  in  the  region  where  the  fever 
occurs.  Ticks  feeding  on  these  get  the  infection  and 
transmit  it  to  man.  The  great  mass  of  ticks  unques- 
tionably become  engorged  on  domestic  animals,  and 
this  suggests  dipping  and  spraying  as  means  of  tick 
control.  Sheep  grazing  diminishes  the  number  of 
ticks,  "for  the  reason  that  ticks  die  upon  sheep, 
and  many  of  the  engorged  females  are  not  fertilized 
on  account  of  the  difficulty  experienced  by  the 
males  in  propelling  themselves  through  the  thick 
wool  in  search  of  the  females.  This  method  has 
been  successfully  tried  in  controlling  the  ticks  and 
the  disease  in  the  Bitter  Root  Valley  in  1914." 

'  Although  the  tick  is  not  a  true  insect,  it  is  classed  with  the 
other  true  insects  that  are  involved  in  this  group  of  diseases. 


CHAPTER  SEVEN 

The  Venereal  Diseases 

Chancroid    Gonorrhea    Syphilis 

The  principal  facts  to  be  learned  in  connection 
with  these  diseases  may  perhaps  be  best  studied  by 
referring  to  the  table  on  the  following  page. 

One  of  the  greatest  difficulties  in  trying  to  check 
the  spread  of  venereal  diseases  is  that  in  many 
instances  the  patient,  beheving  he  has  fully  recovered, 
is  still  a  carrier  of  the  germs.  A  person  having  gonor- 
rhea, for  example,  may  apparently  get  well,  while 
stiU  harboring  the  germs.  In  this  condition,  though 
seemingly  well  himself,  he  can  transmit  the  infection 
to  others.  Thus  wives  sometimes  become  infected 
from  husbands  who  have  supposed  themselves 
recovered  from  the  disease. 

In  connection  with  these  facts  it  may  be  said 
here  that  one  of  the  greatest  causes  of  the  spread 
of  disease  may  be  found  in  the  fact  that  many 
persons,  directly  or  indirectly,  transmit  a  disease 
without  reahzing  it.  The  disease-spreading  Typhoid 
Mary  (page  19)  well  illustrates  this  point.  It  occa- 
sionally happens  that  such  unwitting  spread  of 
disease  brings  about  civil  action  on  the  part  of  the 
victim.  An  interesting  example  of  this  sort  occurred 
a  few  years  ago.  A  man  sued  one  of  our  largest 
railroads  for  $10,000  damages.  He  and  his  family 
had  contracted  smallpox  from  a  section  gang  on  the 
railroad,  and  the  railroad,  it  was  held,  was  liable  for 
damages,  by  allowing  the  disease  to  be  transmitted. 

29 


30 


Forty  Notifiable  Diseases 


Table  3 


Acquired  by  sexual  contact 

Occasionally  by  accident 

Never  hereditary 

May  be  acquired  from  either  parent  at  time  of  conception 

May  be  acquired  from  mother  at  any  time  during  ges- 
tation   

May  be  acquired  from  mother  at  time  of  delivery  ' .    .    . 

Local  (limited,  usually  to  genitalia) 

General 

Begins  local  but  may  reach  remote  parts,  as  bladder,  ure- 
ters, kidneys,  seminal  vesicles,  testes,  or  even  joints, 
causing  what  is  known  as  "gonorrhonl  rheumiitism"  . 

Causing  acute  pain 

Causing  much  blindness 

Causing  many  operations  on  women 

Causing  insanity 

Causing  most  sterility  in  both  sexes      

Causing  most  stillbirths 

Causing  most  varied  symptoms,  as  eruptior.s,  r.orvoi;s 
manifestations 

Most  prevalent 

Relative  prevalence  in  the  United  States 

Always  curable  but  more  or  less  disfiguration 

Curable  when  taken  in  hand  early  (?)      

O(!casionally  totally  refractory  to  treatment 

Apparently  cured,  really  cured 

Apparently  cured,  yet  more  or  less  doubtful  for  a  long 
time 

Treatment  by  cauterization 

Treatment  by  general  measures  and  antiseptics      .    .    . 

Treatment  by  general  measures,  mercurv.  and  salvarsnn 
(606) ■ 


X 


'  In  this  case  it  develops  in  the  eyes  of  the  infant  and  is  known 
MS  uphlhalmia  neonatorum.  Much  blindness  is  directly  due  to  this 
cause,  but  such  blindness  could  be  easily  prevented  by  dropping 
1  {)er  cent  solution  of  silver  nitrate  in  the  eyes  of  the  new-born  child. 


The  Venereal  Diseases  31 

He  who  transmits  a  venereal  disease,  however, 
inflicts  a  far  greater  damage  than  the  raihoad  did, 
and  in  many  cases  he  does  it  (or  rather  takes  the 
chance)  knowingly,  whereas  the  railroad  did  this 
unwittingly.  Would  not  the  transmission  of  venereal 
disease  be  cause  for  civil  action?  WiU  the  trans- 
mission of  venereal  disease  ever  be  cause  for  criminal 
action? 

Early  in  1922  a  bill  was  introduced  into  the 
Reichstag  providing,  among  other  things,  that  "any 
one  who  knows,  or  to  judge  from  his  condition  must 
assume,  that  he  is  suffering  from  an  infectious  sexual 
disease,  and  who,  in  spite  of  the  fact,  exposes  another 
in  the  customary  manner  to  the  danger  of  infection, 
is  subject  to  imprisonment." 


CHAPTER  EIGHT 

Diseases  Affecting  Especially  the  Nervous 
System 

Cerebrospinal  meningiUs  Tetanus 

Poliomyelitis  (infantile  paralysis)       Encephalitis 
Rabies 

These  five  diseases  affect  especially  the  brain 
and  spinal  cord.  Of  the  five,  rabies,  tetanus,  and 
encephalitis  are  considered  elsewhere  (see  Glossary) ; 
cerebrospinal  meningitis  and  infantile  paralysis  will 
be  discussed  briefly  in  this  chapter. 

The  germ  that  causes  cerebrospinal  meningitis  has 
been  known  a  long  time,  but  the  one  that  causes 
infantile  paralysis  has  only  lately  been  isolated  by 
Flexner  and  Noguchi  of  the  Rockefeller  Institute, 
New  York. 

Cerebrospinal  meningitis  (cerebrospinal  fever,  or 
"spotted  fever,"  if  you  choose)  is  an  epidemic  dis- 
ease of  some  importance,  causing  about  six  or  seven 
thousand  deaths  a  year.  In  addition  to  the  deaths 
that  it  causes,  a  large  number  of  the  victims  are 
left  permanent  cripples  of  one  kind  or  another. 

The  epidemic  behavior  of  the  disease  is  rather 
peculiar,^  and  in  this  respect  there  is  only  one  other 
disease  —  infantile  paralysis  —  like  it.  In  1904  an 
outbreak  occurred  in  Madison,  Florida,  which  illus- 

'  The  explanation  that  is  offered  for  such  erratic  lH;havior  is 
that  there  is  a  large  number  of  carriers  among  the  well,  and  that 
of  those  exposed,  only  a  very  few  ever  contract  the  disease.  Although 
admittedly  lame,  this  is  the  In^st  explanation  we  have  to  offer  at 
the  present  time. 

32 


Diseases  of  Nervous  System  33 

trates  this  behavior.  Suddenly,  Hke  a  bolt  from  a 
clear  sky,  a  case  of  the  disease  appeared,  and  then 
another,  and  another;  then  a  death  occurred,  and 
another,  and  another.  Excitement  ran  high.  In  all 
there  were  30  cases  diagnosed,  and  7  deaths. 

Now,  one  of  the  notable  facts  concerning  this 
outbreak  is  that  in  only  two  instances  did  more 
than  one  case  occur  in  a  family,  or  indeed  in  the 
same  household;  and  in  one  of  these  two  instances 
both  cases  appeared  on  the  same  day.  This  is  not 
an  uncommon  phenomenon  in  the  epidemic  behavior 
of  both  cerebrospinal  fever  and  infantile  paralysis. 

Another  notable  phase  of  the  outbreak  is  that 
the  epidemic  rose  like  a  tide  and  then  subsided, 
leaving  nothing  to  show  that  it  had  been  there 
except  the  deaths  and  the  fact  that  one  of  the 
individuals  who  recovered  was  afterward  cross-eyed. 

Another  fact  to  be  noted  is  that  while  this  outbreak 
was  going  on  in  Madison,  there  was,  6  miles  away 
in  the  country,  a  httle  girl  who  had  the  disease, 
although  she  had  not  been  to  Madison  for  half  a 
year;  also,  there  was  another  case  12  miles  in  another 
direction;  there  were  two  more  over  100  miles  away 
in  Columbia  County;  and  about  200  miles  away  in 
Marion  County  there  was  still  another  one.  But  the 
center  of  the  storm  was  at  Madison. 

Now,  in  a  general  way,  this  is  what  happens  in 
most  outbreaks  of  meningitis.  There  is  a  center 
where  the  disease  reaches  its  maximum  of  intensity; 
but  sprinkled  round  at  varying  distances  and  with 
no  seeming  connection  there  are  a  few  other  cases. 


34  Forty  Notifiable  Diseases 

Infantile  paralysis  behaves  in  the  same  way.  We 
may  go  for  years  without  a  case;  then  without  warn- 
ing there  is  an  outbreak.  There  is  always  a  focus 
more  intense  than  elsewhere,  and  radiating  out  from 
that  focus  other  cases  are  encountered  in  varying 
numbers. 

Infantile  paralysis  does  not  cause  so  many  deaths 
as  it  does  permanent  cripples.  Certain  nerves  in 
the  spinal  cord  become  paralyzed,  and  then  the  mus- 
cles presided  over  by  these  nerves  become  para- 
lyzed. The  disease  often  comes  on  suddenly.  A  child 
may  be  quite  well,  to  all  appearances,  and  then  per- 
haps miss  a  meal  and  possibly  have  a  little  fever 
for  a  day  or  so;  then  it  is  soon  noticed  that  the 
child  does  not  use,  say,  a  foot,  or  leg,  or  arm  —  so 
insidious  is  the  disease. 


CHAPTER  NINE 

Diseases  Contracted  from  Lower  Animals 

Actinomycosis  Rabies 

Anthrax  Rocky  Mountain  spotted 

Glanders  fever 

Plague  Trichinosis 

Of  these  seven  diseases,  only  rabies  will  be  con- 
sidered here.  Information  regarding  the  other  six 
diseases,  and  also  additional  information  on  rabies, 
may  be  had  by  referring  to  the  Glossary. 

Rabies,  or  hydrophobia,  is  a  disease  to  which 
probably  all  warm-blooded  animals  are  susceptible. 
Dogs  chiefly  get  it,  but  less  often  cats,  cows,  horses, 
and  other  domestic  animals.  It  sometimes  gets 
started  among  wild  animals,  as  wolves,  and  plays 
havoc  with  them. 

The  germ  causing  the  disease  is  not  known,  but 
it  is  known  that  the  brain  and  spinal  cord  are  the 
parts  chiefly  attacked.  An  Italian  by  the  name  of 
Negri  found  in  the  brain  and  spinal  cord  of  animals 
affected  with  rabies  certain  little  bodies,  since  known 
as  "Negri  bodies."  These  we  know  are  connected 
in  some  way  with  rabies;  indeed,  they  may  be  the 
germs  themselves.  They  have  been  found  in  the 
brain,  spinal  cord,  and  sahva  of  animals  affected 
with  rabies,  but  nowhere  else.  The  disease  is  trans- 
mitted through  the  bite  of  an  infected  animal. 

When  a  dog's  head  is  sent  to  the  laboratory  to 
be  examined  for  rabies,  it  is  these  little  "Negri 
bodies"  that  are  hunted  out.    If  the  bacteriologist 

35 


36  Forty  Nolifiable  Diseases 

finds  them,  he  reports  back  that  the  animal  had 
rabies.  But  sometimes  he  cannot  find  them;  then 
he  does  not  know  whether  the  animal  had  rabies 
or  not,  for  it  should  be  understood  that  these  Negri 
bodies  are  very  scarce  the  first  day  or  so  after  the 
disease  develops.  The  bacteriologist  might  hunt  for 
hours  and  hours  and  still  not  find  them.  But  as 
the  disease  progresses  in  the  animal,  the  bodies 
become  more  and  more  abundant,  and  by  the  time 
death  takes  place  they  are  usually  numerous  and 
easy  to  find. 

Thus  it  is  apparent  that  if  tlie  bacteriologist  Jails 
to  find  the  Negri  bodies^  he  cannot  pronounce  the  animal 
free  from  the  disease. 

The  practical  lesson  to  be  learned  from  these 
facts  is  that  when  an  animal  is  suspected  of  having 
rabies,  do  not  kill  him,  but  shut  him  up  and  wait. 
He  is  your  best  witness.  If  you  kill  your  witness 
and  then  the  laboratory  fails  to  find  the  Negri 
bodies,  you  will  never  know  whether  the  animal 
was  mad  or  not.  Shut  him  up  instead,  and  if  he 
has  radjies  he  will  get  rapidly  worse  and  will  die 
in  4  or  5  days  with  unmistakable  symptoms.  You 
will  then  know  what  you  are  dealing  with. 


CHAPTER  TEN 

Diseases  Having  a  Well-defined  Geographical 
Limitation 

Malaria    Hookworms   Rocky  Mountain  spotted  fever 

If  you  were  to  draw  a  line  through  a  map  of  the 
United  States  from  top  to  bottom  at  about  the 
middle  of  the  map,  and  then  another  line  from 
right  to  left  at  about  the  middle,  the  area  would 
be  blocked  out  in  four  quadrants  —  northeast,  south- 
east, northwest,  and  southwest.  The  southeast  quad- 
rant is  the  area  of  endemic  malaria  in  the  United 
States.  Except  for  a  little  territory  in  New  York 
and  New  Jersey,  and  another  small  area  in  California, 
malaria  is  limited  to  the  southeast  quadrant.  Why? 
Why  is  it  not  found  in  Maine,  or  Minnesota,  or 
Colorado?  The  answer  is  not  far  to  seek.  In  Maine 
there  is  enough  rain,  but  it  is  too  cold.  In  Minnesota 
there  is  also  rain,  but  it  likewise  is  cold.  In  Colorado 
it  is  warm  enough,  but  there  is  not  much  rain. 

Two  conditions  for  malaria  are  required:  water  in 
which  mosquitoes  can  breed  and  a  reasonably  warmth. 
In  the  southeast  quadrant  those  conditions  are 
fulfilled.  It  is  the  one  quarter  of  the  United  States 
that  has  an  abundance  of  both  warmth  and  moisture. 
In  the  Sacramento  and  San  Joaquin  valleys  there 
is  enough  moisture  to  provide  a  mosquito  fauna, 
and,  as  is  to  be  expected,  there  is  malaria. 

Centering  around  New  York  and  New  Jersey  is 
an  area  more  or  less  famous  for  mosquitoes.  One 
would  naturally  expect  an  area  of  malaria  there. 

37 


38  Forty  Notifiable  Diseases 

Regarding  this  area,  the  United  States  Public  Health 
Service  says:  *'0f  the  two  smaller  endemic  areas 
(of  malaria),  one  includes  a  section  of  the  northern 
part  of  New  Jersey,  southeastern  New  York,  Connec- 
ticut, Rhode  Island,  and  part  of  the  state  of  Massa- 
chusetts." 

The  hookworm  is  even  more  sensitive  to  environ- 
mental conditions  than  the  malarial  mosquito,  and 
is  a  little  more  restricted  in  habitat.  Like  malaria, 
the  hookworm  occupies  the  southeast  quadrant  of 
the  United  States,  and  like  malaria  it  has  a  little 
patch  in  California  where  warmth  and  moisture 
prevail.  But  unlike  malaria  it  has  no  foothold  in 
New  York  and  New  Jersey.  The  two  conditions 
required  for  malaria  are  even  more  necessary  for 
the  propagation  of  hookworms. 

Such  is  the  distribution  of  hookworms  in  the 
United  States.  If  you  want  a  clear  picture  of  their 
distribution  over  the  whole  world,  just  imagine  a 
globe  with  the  torrid  zone  widened  out  from  47 
degrees  to  80  de^ees,  and  you  will  have  the  potential 
habitat  of  this  parasite.  It  is  true  that  in  this  zone 
there  are  great  stretches  of  desert  where  the  hook- 
worm could  not  exist.  Even  the  highly  porous  soil 
of  portions  of  southern  Florida  dries  out  so  quickly 
that  the  hookworm  cannot  survive.  In  this  great 
belt  there  are  also  mountains  that  have  a  mean 
temperature  entirely  too  low  for  the  hookworms; 
but  in  a  general  way,  taking  into  consideration  the 
exceptions  noted,  this  belt  represents  the  hookworm 
zone  of  the  world. 


Geographical  Limitation  39 

The  third  and  last  of  the  forty  notifiable  diseases 
that  have  a  geographical  limitation  is  Rocky  Moun- 
tain spotted  fever.  This  disease  prevails  in  the  bitter 
Root  Valley  of  Montana,  and  to  a  less  extent  in 
the  neighboring  states  of  Idaho,  Wyoming,  California, 
and  Washington. 

It  will  be  recalled  that  it  is  transmitted  by  ticks, 
of  the  species  Dermacentor  andersoni.  These  ticks 
infest  both  the  wild  and  the  domesticated  animals 
in  this  region,  and  occasionally  they  get  the  infection 
from  some  of  these  animals  and  in  turn  may  transmit 
it  to  man.  The  parasite  itself  is  unknown. 

Maver  has  shown  by  experiment  that  other  kinds 
of  ticks  may  also  become  carriers  of  the  disease. 
He  found  that  ticks  collected  in  three  widely  sepa- 
rated states  —  Utah,  Missouri,  and  Massachusetts  — 
were  capable  of  trananitting  the  infection.  There 
is,  therefore,  no  apparent  reason  why  the  parasite 
should  occupy  such  a  hmited  area  as  it  does  at 
present.  In  time  it  may  come  to  occupy  a  larger 
one  —  no  one  can  say. 


CHAPTER  ELEVEN 

Diseases  of  Unknown  Causation 
Cancer  Pellagra 

Besides  cancer  and  pellagra  there  are  many  other 
diseases,  the  cause  of  which  is  unknown.  We  do 
not  know,  for  example,  the  cause  of  measles,  whoop- 
ing-cough, or  smallpox;  but  although  the  germ 
causing  these  diseases  is  unknown,  we  are  neverthe- 
less sure  that  they  are  germ  diseases.  On  the  other 
hand,  cancer  is  not  even  suspected  of  being  caused 
by  a  germ;  pellagra  is  thought  to  be  of  dietary 
origin,  but  there  is  no  certainty  about  the  cause 
of  either  of  them. 

As  cancer  is  by  far  the  more  important  of  the 
two  diseases  listed  at  the  head  of  this  chapter,  we 
shall  devote  most  of  our  time  to  a  consideration  of 
it.  A  few  facts  concerning  the  disease  may  be  learned 
by  referring  to  page  65. 

Cancer  is  a  much  more  important  disease  than 
the  majority  of  people  generally  think  it  to  be.  A 
comparison  with  some  of  the  other  diseases  will 
show  its  importance.  Turning  to  the  table  on  page 
11  listing  the  forty  notifiable  diseases  in  the  order 
of  the  number  of  deaths  that  they  cause,  we  note 
that  the  four  leading  causes  in  1917  were  tuberculosis, 
pneumonia,  cancer,  and  influenza.  It  will  be  observed 
that  the  first  three  diseases  cause  60,000  deaths,  or 
over,  in  a  year;  and  then  for  the  fourth  disease 
there  is  a  sudden  drop  to  one  fifth  that  number. 
Cancer  accordingly  stands  third  highest  among 
these  causes  of  deaths. 

40 


Diseases  of  Unknown  Causation  41 

It  has  been  found  that  the  number  of  deaths  from 
cancer  is  increasing.  The  number  of  deaths  from 
pneumonia  is  also  increasing,  but  at  a  less  rapid 
rate.  Thus,  if  the  present  rate  keeps  up,  within  a 
measurable  time  cancer  will  take  its  place  as  the 
leading  cause  of  death  in  the  United  States. 

Women  are  affected  much  more  than  men.  It  is 
easy  to  remember  that  the  death  rate  from  cancer 
among  women  is  1)^  times  that  among  men. 

Cancer  is  essentially  a  disease  of  advancing  years. 
Over  ten  times  as  many  cases  occur  above  the  age 
of  45  as  below  it. 

What  every  one  wants  to  know  is  whether  cancer 
is  hereditary,  or  as  the  laymen  are  learning  to  frame 
the  question  now,  whether  a  "predisposition  to 
cancer"  is  hereditary.  The  subject  has  been  investi- 
gated by  the  Medico-Actuarial  Committee,  and  their 
findings  are  of  interest.  The  Committee  studied  a 
group  of  persons  with  a  history  of  two  or  more 
cases  of  cancer  in  the  family.  The  expected  death 
rate  in  this  group  was  87.3.  The  actual  death  rate 
proved  to  be  only  69,  and  of  these  only  4  were  from 
cancer. 

In  1914  there  was  formed  in  New  York  City  the 
American  Society  for  the  Control  of  Cancer.  Dr. 
Frederick  L.  Hoffman,  of  the  Prudential  Insurance 
Company  of  America,  is  and  has  been  a  leading 
spirit  in  that  organization.  The  Society  has  issued 
a  leaflet  under  the  caption,  "Vital  Facts  about 
Cancer."  The  following  excerpts  are  from  that 
leaflet: 


42  Forty  Notifiable  Diseases 

"During  the  Great  War  the  United  States  lost 
about  80,000  soldiers.  During  the  same  two  years 
180,000  people  died  of  cancer  in  this  country.  Cancer 
is  now  kiUing  one  out  of  every  ten  persons  over 
40  years  of  age. 

"Many  of  these  deaths  are  preventable,  since 
cancer  is  frequently  curable,  if  recognized  and  prop- 
erly treated  in  its  eariy  stages. 

"Cancer  begins  as  a  small  local  growth  which 
can  often  be  entirely  removed  by  competent  surgical 
treatment,  or,  in  certain  external  forms,  by  using 
radium,  the  X-ray,  or  other  methods. 

"Cancer  is  not  a  constitutional  or  'blood'  disease; 
there  should  be  no  thought  of  disgrace  or  of  'heredi- 
tary taint'  about  it. 

''Cancer  is  not  a  communicable  disease.  It  is  not 
possible  to  'catch'  cancer  from  one  who  has  it. 

''Cancer  is  not  inherited.  It  is  not  certain  even 
that  a  tendency  to  the  disease  is  inherited.  Cancer 
is  so  frequent  that  simply  by  the  law  of  chance 
there  may  be  many  cases  in  some  fEunilies,  and  this 
gives  rise  to  much  needless  worry  about  inheriting 
the  disease. 

"The  beginning  of  cancer  is  usually  painless;  for 
this  reason  its  insidious  onset  is  frequently  overiooked 
and  is  too  easily  neglected.  Other  danger  signals 
must  be  recognized  and  competent  medical  advice 
obtained  at  once." 

Then  the  authors  enumerate  some  of  the  signals: 

Lump  in  the  breast.  "Every  persistent  lump  in 
the  breast  is  a  warning  sign.    All  such  lumps  are 


Diseases  of  Unknown  Causation  43 

by  no  means  cancer,  but  even  innocent  tumors  of 
the  breast  may  turn  into  cancer  if  neglected." 

Discharge  or  bleeding.  "In  women,  continued  un- 
usual discharge  or  bleeding  requires  the  inunediate 
advice  of  a  competent  doctor.  The  normal  change 
of  hfe  is  not  accompanied  by  increasing  flowing, 
which  is  always  suspicious.  ..." 

Sore  that  does  not  heal.  "Any  sore  that  does  not 
heal,  particularly  about  the  mouth,  lips,  or  tongue, 
is  a  danger  signal.  Picking  or  irritating  such  sores, 
cracks,  ulcerations,  etc.,  or  by  treating  these  skin 
conditions  with  home  remedies,  pastes,  poultices, 
caustics,  etc.,  is  playing  with  fire.  Warty  growths, 
moles,  or  other  birthmarks,  especially  those  subject 
to  constant  irritation,  should  be  attended  to  imme- 
diately if  they  change  in  color  or  appearance  or 
start  to  grow." 

Indigestion.  "Persistent  indigestion  in  middle 
hfe,  with  loss  of  weight  and  change  of  color,  or 
with  pain,  vomiting,  or  diarrhea,  call  for  thorough 
and  competent  medical  advice  as  to  the  possibility 
of  internal  cancer." 

As  to  pellagra,  there  is  not  much  to  be  said.  Its 
exact  cause  is  not  known.  Some  theories  about  it 
may  be  mentioned. 

The  "spoiled  maize"  (cornbread)  theory,  first 
proposed  by  Lombroso,  a  great  Itahan  scholar. 
This  theory  is  now  generally  abandoned. 
The  "sandfly"  theory,  proposed  by  Sambon, 
an  Englishman.  Sambon  thought  the  epidemio- 
logical evidence  sufiicient  to  convict  the  sandfly 


ii  Forty  Notifiable  Diseases 

of  transmitting  the  disease.    This  theory  also 

is  now  abandoned. 
Other  minor  theories  have  been  proposed,  but  we 
are  not  interested  in  them.  At  present  the  prevailing 
opinion  is  that  the  disease  has  some  connection  with 
the  diet.  Certain  it  is  that  treatment  addressed  to 
correction  of  all  errors  of  diet  has  been  the  most  suc- 
cessful. It  is  well  to  remember  that  pellagra  has 
three  groups  of  symptoms: 

1.  Nervous  symptoms,  which  may  consist  of 
anything  from  hot  or  cold  sensations  on  the 
one  hand,  to  insanity  at  the  other  extreme. 

2.  Intestinal  symptoms. 

3.  Eruption. 

In  a  given  case  any  of  these  symptoms  may  be 
partly  or  wholly  suppressed. 


CHAPTER  TWELVE 

Some  Diseases  Which  May  Be  Spread  by 
Carriers 


Diphtheria 

Paratyphoid 

Gonorrhea 

Pneumonia 

Influenza 

Poliomyelitis 

Malaria 

Syphilis 

Meningitis 

Typhoid 

When  a  person  gets  well  from  a  communicable 
disease,  he  usually  gets  rid  of  the  germs  causing  it. 
This  is  particularly  true  in  such  diseases  as  measles, 
whooping-cough,  and  smallpox. 

But  in  some  other  diseases  this  is  not  the  case  at 
all.  In  diphtheria,  for  example,  the  person  may  get 
well  and  still  retain  the  germs;  in  other  words,  he 
becomes  immune  to  the  diphtheria  germs,  but  the 
germs  themselves  continue  to  grow  in  his  throat  for 
weeks  or  months.  Such  persons  are  called  "diph- 
theria carriers."  Ehrhch,  the  great  German  investi- 
gator, used  to  speak  of  such  cases  as  having  "immu- 
nity without  sterilization." 

It  should  be  understood  that  aU  cases  of  diphtheria 
do  not  terminate  as  carriers,  but  that  quite  a  number 
do.  Moreover,  some  persons  become  carriers  of 
diphtheria  without  ever  having  had  the  disease,  or 
at  least  without  knowing  that  they  had  it.  Such 
persons  might  have  had  a  mild  attack  that  went 
undetected,  or  may  never  have  had  it  at  all.  Never- 
theless, they  are  carriers  and  are  capable  of  trans- 
mitting the  disease  to  susceptible  persons. 

45 


46  Forly  Notifiable  Diseases 

Tliese  fads  apply  with  equal  force  to  all  the 
diseases  at  the  head  of  this  chapter.  In  each  case 
a  person  may  be  a  distributor  of  the  infection  after 
having  had  the  disease  in  question,  or  he  may  be 
a  distributor  even  though  there  is  no  history  of  his 
having  had  the  disease. 


CHAPTER  THIRTEEN 
Diseases  Due  to  Filterable  Viruses 


Dengue 

Scarlet  fever  (?)i 

Measles 

Smallpox 

Poliomyelitis 

Trachoma 

Rabies 

Yellow  fever 

The  word  "virus"  does  not  have  a  very  sharply 
defined  meaning.  It  was  formerly  applied  particu- 
larly to  the  germs  of  smallpox  and  cowpox.  As  long 
as  the  germ  of  a  communicable  disease  is  unknown, 
it  is  commonly  referred  to  as  the  "virus." 

A  "filterable  virus"  is  one  that  will  go  through 
a  special  filter,  made  of  unglazed  porcelain  or  diato- 
maceous  earth,  that  filters  out  ordinary  bacteria. 
There  are  several  kinds  of  these  special  filters  in 
the  market,  as  the  "Berkefeld"  and  the  "Chamber- 
land,"  of  which  the  pores  are  so  fine  that  while  they 
will  let  liquid  through,  they  will  hold  back  all  ordinary 
germs  —  one  could  almost  say  all  known  germs.  In- 
deed, one  could  have  said  so  until  recently,  but  now 
that  Noguchi  has  discovered  the  germ  of  yellow 
fever,  and  Flexner  and  Noguchi  together  have  found 
the  germ  of  poHomyehtis,  exception  has  to  be  made 
of  these  two. 

*  Not  only  here,  but  generally  throughout  this  book,  the  interroga- 
tion point  implies  a  degree  of  doubt. 


47 


CHAPTER  FOURTEEN 
Nine  Diseases  Amenable  to  Immunization 


Asiatic  cholera 

Rabies 

Bubonic  plague 

Smallpox 

Paratyphoid 

Diphtheria 

Typhoid 

Tetanus 

Anthrax 

It  is  quite  possible  to  obtain  immunity  against 
several  of  the  notifiable  diseases.  Of  the  nine  listed 
above,  a  person  can  be  immunized  against  the  first 
four  —  Asiatic  cholera,  bubonic  plague,  paratyphoid, 
and  typhoid  —  by  the  injection  of  a  dead  culture 
of  the  germs  causing  the  disease;  for  the  next  three  — 
anthrax,  rabies,  and  smallpox  —  living  attenuated 
organisms  are  used  to  obtain  immunity;  and  for  the 
last  two  —  diphtheria  and  tetanus  —  an  antitoxin 
is  effective. 

Immunity  may  be  acquired  against  two  of  these 
diseases  —  Asiatic  cholera  and  bubonic  plague  —  in 
more  than  one  way;  namely,  by  the  use  of  dead 
cultures  and  by  the  use  of  living  attenuated  organ- 
isms. But  however  they  may  be  varied  or  combined, 
there  are  at  bottom  only  the  three  methods  above 
mentioned  of  producing  artificial  immunity. 

The  simplest  method  is  by  the  injection  of  dead 
cultures  of  the  germs  causing  the  disease.  But 
before  going  into  that  let  me  give  you  a  theory  that 
has  been  advanced.  This  is  not  accepting  it  or 
rejecting  it,  understand,  but  merely  stating  it. 
According  to  this  theory,  living  germs  of  typhoid 
do  not  hurt  one — it  is  only  after  they  die  and  disin- 

48 


Diseases  Amenable  to  Immunization       49 

tegrate  that  the  poison  which  causes  the  symptoms 
of  the  disease  is  set  free.  When  we  have  typhoid 
fever,  it  is  not  the  living  germs  but  the  dead  ones  that 
make  us  sick.  Of  the  living  germs  in  our  bodies, 
some  are  multiplying,  some  are  dying;  but  the  living 
ones  contribute  to  the  disease  only  in  furnishing  more 
and  more  germs  to  die,  while  in  turn  the  dead  ones 
are  the  real  cause  of  the  trouble.  And  it  is  the  dead 
ones  that  cause  the  immunity  to  develop. 

According  to  this  theory,  then,  when  dead  typhoid 
germs  are  injected  into  the  body,  the  patient  is 
virtually  given  a  little  sKce  of  typhoid  fever.  These 
dead  germs  cause  the  immunizing  substances  to 
appear  in  the  blood,  after  which  the  person  is  immune. 
For  typhoid  fever  is  Uke  smallpox  in  that  a  person 
ordinarily  has  it  only  once. 

The  typhoid  germs  that  are  used  in  inoculating 
against  the  disease  are  grown  in  the  laboratory,  and 
then  killed  by  heat  and  a  small  quantity  injected 
into  the  individual.  After  a  week  to  ten  days  a 
second  dose  is  given,  and  then  a  third.  Paratyphoid 
is  prevented  in  the  same  way. 

For  Asiatic  cholera  there  are  two  methods  of 
immunization  —  one  by  the  injection  of  dead  germs, 
as  in  typhoid,  and  the  other  by  the  use  of  "attenu- 
ated" germs,  similar  to  the  method  used  in  vaccinat- 
ing against  anthrax,  which  we  shall  discuss  shortly. 

For  plague  also  there  are  two  methods,  with  some 
additional  variations.  The  first  and  chief  method, 
known  as  Haffkine's,  consists  of  injections  of  dead 
plague  germs,  just  as  dead  typhoid  germs  are  in- 


50  Forly  Notifiable  Diseases 

jected  to  inununize  against  typhoid.  A  second 
method  —  that  of  giving  attenuated  germs  —  has 
also  been  used.  The  next  paragraph  will  make  clear 
the  details  of  the  method  of  giving  attenuated  germs. 
When  we  turn  to  anthrax,  rabies,  and  smallpox, 
we  find  that  immunization  is  obtained  by  giving 
attenuated  germs  only.  In  this  method  the  germs 
are  alive,  but  before  they  are  injected  they  must 
be  weakened  —  "attenuated,"  as  it  is  called.  Now 
this  method  was  not  learned  in  a  day.  Indeed,  it 
required  a  quarter  of  a  century  of  study  by  scientific 
men  to  bring  the  idea  to  full  fruition.  Devaine  and 
Rayer,  Koch,  Delafond,  and  Jaillard  are  some  of 
the  names  that  will  be  forever  associated  with  the 
history  of  the  anthrax  germ.  But  t-o  Louis  Pasteur 
belongs  the  honor  of  having  won  a  complete  victory 
over  it.  Without  going  into  the  various  experiments 
or  steps,  but  merely  stating  the  result,  Pasteur  found 
that  he  could  attenuate  anthrax  germs  by  growing 
them  in  neutral  chicken  broth  at  a  temperature  of 
42  or  43  degrees  (centigrade)  in  the  presence  of  air. 
Thus  grown  they  would  not  form  "spores"^  and 
would  gradually  cease  to  grow  and  ultimately  die;  but 

•  "Spores"  of  germs  correspond  roughly  fo  the  seeds  of  higher 
plants.  \\  hen  spore-forming  gerins  (nil  germs  do  not  form  spores), 
as  the  anthrax  germs,  for  example,  are  grown  under  certain  condi- 
tions, a  tiny  body  develops  in  each  germ,  and  then  the  rest  of  the 
germ  disappears  and  only  this  little  body  —  known  as  the  spore  — 
is  left.  It  is  very  resistant  to  unfavorable  conditions.  It  may  remain 
dormant  for  years,  and  then  when  brought  into  favorable  environ- 
ments it  will  revive  and  begin  to  grow  and  reproduce.  When  Pasteur 
was  working  with  anthrax  it  was  known  that  certain  pastures  were 
rated  as  dangerous,  for  cattle  that  grazed  upon  them  would  sooner 
or  later  develop  anthrax  in  the  herd.    It  was  customary  at  that 


Diseases  Amenable  to  Immunization       51 

before  the  cultures  were  finally  dead,  they  could 
be  injected  into  susceptible  animals  and  the  disease 
produced  in  mild  form.  The  animals  thus  treated 
were  afterward  found  to  be  immune  to  virulent 
germs. 

It  is  not  customary  to  immunize  human  beings 
against  anthrax,  but  of  course  it  could  be  done. 

As  to  rabies,  the  germ  itself  is  not  known  and 
cannot  therefore  be  grown  in  the  laboratory;  but 
Pasteur  found  that  the  virus  is  present  in  the  brain 
and  spinal  cord  of  an  animal  affected  with  the  dis- 
ease. The  way  he  proved  this  was  by  injecting  a 
small  portion  of  the  brain  or  spinal  cord  of  such 
an  animal  into  a  well  animal  (which  we  will  call 
No.  2).  For  this  experiment  he  used  the  rabbit  by 
preference.  He  found  that  rabbit  No.  2  would  develop 
rabies  in  about  14  days.  Then  he  found  that  he 
could  inject  a  smaU  bit  of  the  cord  of  animal  No.  2 
into  a  third  animal  (No.  3)  and  this  would  produce 
rabies  in  just  a  little  less  time  than  in  No.  2;  No.  4, 
he  found,  would  come  down  in  still  less  time,  and 
when  he  had  passed  it  through  about  50  rabbits, 
the  incubation  period  was  reduced  to  6  days.  But 
try  as  he  would  he  could  not  reduce  the  incubation 
period  below  6  days. 

time  to  bury  all  animals  that  died  of  anthrax.  This  measure  was 
thought  sufficient  to  rid  the  herd  of  the  infection.  But  Pasteur 
found  that  above  the  graves  of  these  buried  animals  he  could  isolate 
these  spores  from  the  soil,  even  years  after  the  animals  had  been 
buried  and  crops  had  been  grown  over  the  grave.  But  how  the 
spores  could  get  up  to  the  surface  from  the  animal  buried  3  to  6 
feet  deep  was  at  first  a  mystery.  Pasteur  showed,  however,  that 
earthworms  brought  them  up. 


52  Forly  Notifiable  Diseases 

Now,  let  us  see  just  what  happened.  By  passing 
the  virus  through  rabbits  he  increased  its  virulence; 
in  other  words,  he  made  it  stronger  or,  as  the  bac- 
teriologists say,  "exalted  the  virus."  The  more 
"exalted"  the  virus,  the  quicker  it  will  produce 
death. 

Having  "exalted"  the  virus  by  passing  it  through 
rabbits,  Pasteur  undertook  to  "unscramble  the 
eggs";  that  is,  to  weaken  the  virus  or  attenuale  it. 
This  he  succeeded  in  doing  by  a  method  of  drying. 
He  took  the  spinal  cord  of  a  rabbit  that  had  died 
of  rabies,  and  dried  it  14  days;  then  he  found  that 
he  could  inject  it  into  another  rabbit  and  it  would 
not  produce  rabies  at  all.  The  year  before  this, 
Pasteur  had  attenuated  anthrax  germs  by  growing 
them  in  an  unsuitable  temperature.  Now,  he  had 
attenuated  rabies  virus  by  drying. 

When  Pasteur  had  attenuated  anthrax  germs,  it 
was  only  another  step  to  protecting  an  animal  against 
anthrax.  All  he  had  to  do  was  to  inject  a  few  of 
these  attenuated  germs,  and  the  animal  would  have 
a  very  mild  case  of  the  disease  —  hardly  get  sick  at 
all;  and  after  that  he  would  be  immune  to  anthrax. 
But  to  produce  immunity  against  rabies  was  not  so 
simple.  He  knew  the  virus  was  safe  when  it  had 
been  dried  14  days.  So  he  began  by  giving  an  animal 
an  injection  of  cord  that  had  been  dried  2  weeks. 
Then  the  next  day  he  gave  an  injection  that  had 
been  dried  only  13  days;  the  dose  the  next  day  had 
been  dried  12  days;  then  11,  10,  9,  8,  and  7,  and 
on  down  to  a  perfectly  fresh  cord  that  had  not  been 


Diseases  Amenable  to  Immunization       53 

dried.  But  the  rabbit  showed  no  signs  of  the  disease 
at  all!  And  yet  this  last  dose,  you  will  remember, 
was  a  fresh  cord  that  had  not  been  dried  —  one  that 
would  ordinarily  produce  rabies  in  6  days! 

This  was  Pasteur's  victory  over  rabies.  He  could 
immunize  a  person  against  this  dread  disease  in 
about  3  weeks.  Thus  we  have  what  is  known  today 
as  the  "Pasteur  treatment."  The  scheme  of  injec- 
tions has  been  changed  somewhat  —  for  instance, 
we  do  not  begin  with  a  14-day  cord  —  but  the  prin- 
ciple is  unchanged.  It  is  another  method  of  pro- 
ducing inununity  by  the  use  of  a  Hving  attenuated 
virus. 

At  the  time  these  experiments  of  Pasteur's  were 
being  carried  out  (about  1875-80)  persons  had  been 
vaccinated  against  smallpox  for  nearly  100  years, 
but  nobody  understood  it.  All  that  was  known  was 
that  there  was  something  between  smallpox  and  cow- 
pox,  and  that  when  one  had  cowpox  he  became  im- 
mune to  smallpox.  Edward  Jenner,  who  first  vac- 
cinated with  cowpox  to  prevent  smallpox,  suspected 
that  cowpox  was  a  modified  form  of  smallpox,  but 
had  no  evidence  to  support  it.  Pasteur's  work  with 
anthrax  and  rabies  gave  support  to  the  theory,  but 
it  was  later  experiments  that  brought  forth  the  proof. 
It  has  now  been  shown  that  one  can  vaccinate  a  calf 
from  a  smallpox  patient,  and  from  that  first  calf 
vaccinate  a  second  calf;  from  the  second  calf,  a  third, 
and  so  on  until  after  a  while  a  regular  strain  of 
vaccine  will  be  produced.  Here  we  have  another 
example  of  attenuation,  but  in  this  case  it  is  brought 


54  Forly  Notifiable  Diseases 

about  by  passing  the  virus  through  the  skin  of  the 
calf. 

In  actual  practice,  then,  we  have  three  methods  of 
attenuation:  for  anthrax,  by  growing  the  germs  at 
a  high  temperature;  for  rabies,  by  drying;  and  for 
smallpox,  by  passing  through  the  skin  of  the  calf. 
In  each  case  we  produce  immunity  by  using  the 
living  organism,  but  in  an  attenuated  form. 

When  we  come  to  diphtheria  and  tetanus  we  find 
that  immunization  is  brought  about  by  the  injection 
of  antitoxin.  This  method  is  known  as  "passive 
immunization."  To  understand  this,  it  is  necessary 
to  know  something  of  the  production  of  antitoxin. 

Suppose  we  wanted  to  produce  some  diphtheria 
antitoxin.  We  should  proceed  in  the  following 
manner: 

First,  we  should  get  some  diphtheria  germs.  We 
could  get  these  from  the  throat  of  any  child  having 
diphtheria.  Next,  we  should  plant  these  germs  in 
suitable  liquid  in  the  laboratory,  and  they  would 
increase  in  numbers  until  the  liquid  became  a  mass 
of  diphtheria  germs.  Then  we  should  filter  the  germs 
out  by  running  the  liquid  through  a  fine  strainer  —  so 
fine  that  the  germs  could  not  pass. 

It  would  now  be  found  that  if  this  liquid  were 
injected  into  a  susceptible  animal,  it  would  cause 
symptoms  of  diphtheria.  Let  us  see  what  really 
happens.  While  the  diphtheria  germs  were  growing 
in  the  liquid,  they  were  throwing  off  the  diphtheria 
poison,  and  this  poison  is  still  in  the  liquid.  Now 
let  us  throw  away  the  germs  which  we  have  filtered 


Diseases  Amenable  to  Immunization       55 

out,  for  it  is  the  poison  thrown  off  while  the  diph- 
theria germs  were  growing  that  we  are  interested  in. 
This  poison  is  called  diphtheria  toxin.  It  is  the  same 
thing  that  the  germs  are  throwing  off  while  growing 
in  the  throat  of  a  child  ill  with  diphtheria,  and  it 
is  the  absorption  of  this  toxin  by  the  child  that  makes 
him  sick. 

Having  now  a  supply  of  this  diphtheria  toxin, 
we  first  inject  a  little  of  it  into  a  horse.  It  makes 
him  slightly  sick,  but  he  soon  recovers  because  the 
dose  is  small.  When  he  gets  well  he  is  given  another 
dose  —  a  little  larger  this  time.  As  soon  as  he  re- 
covers from  this  dose,  he  is  given  a  third,  and  a 
fourth,  and  so  on.  He  is  injected  now  about  twice 
a  week  for  two  or  three  months;  the  dose  of  toxin 
is  made  larger  and  larger  with  each  injection,  until 
finally  he  can  take  great  quantities  without  being 
hurt  by  it.  He  is  immune  against  diphtheria 
toxin. 

Now  it  has  been  found  that  if  this  horse  is  bled 
and  a  little  of  his  blood  mixed  with  diphtheria  toxin, 
the  latter  is  destroyed.  If  the  toxin  thus  treated  is 
then  injected  into  another  horse  or  into  some  other 
animal,  it  produces  no  symptoms  at  all.  The  blood 
of  the  inamune  horse  acts  on  the  toxin  as  water 
acts  on  a  fire  —  it  "puts  it  out,"  so  to  speak.  The 
blood  of  a  horse  that  has  not  been  injected  with 
this  toxin  and  immunized  will  not,  of  course,  act 
in  this  way;  it  is  only  the  blood  of  an  immune  horse 
that  is  effective.  This  shows  that  while  the  horse 
is  being  immunized  a  new  something  is  being  added 


56  Forty  Notifiable  Diseases 

to  his  blood,  something  that  will  overcome  the 
diphtheria  toxin  or  poison. 

This  new  ingredient,  it  has  been  found,  is  thor- 
oughly mixed  with  the  hquid  portion  of  the  blood, 
for  the  corpuscles  can  all  be  strained  out  and  the 
serum  will  still  overcome  the  diphtheria  toxin.  Tliis 
new  something  has  been  given  a  name  —  it  is  called 
antitoxin  because  it  is  against  toxin  and  overcomes  it. 

Now  bear  in  mind  that  the  toxin  comes  from  the 
growing  diphtheria  germs,  and  this  toxin  is  injected 
into  a  horse  again  and  again  until  he  is  immune 
against  it;  that  is,  large  quantities  can  be  injected 
and  it  will  not  hurt  him.  Then  in  the  blood  of  this 
immune  horse  we  find  antitoxin,  the  substance  that 
will  overcome  the  toxin. 

Tlie  horse  is  now  bled  and  his  serum  put  up  in 
bottles  ready  for  use.  Let  us  see  when  and  how  it 
is  used.  Suppose  it  is  suspected  that  a  child  has 
diphtheria.  The  doctor  takes  a  little  "smear"  from 
the  child's  throat  and  sends  it  to  the  laboratory. 
This  specimen  is  examined  under  the  microscope, 
and  if  diphtheria  germs  are  found,  it  is  known  for 
a  certainty  that  the  child  has  diphtheria.  It  will 
be  remembered  that  while  the  diphtheria  germs  are 
growing  in  the  throat  they  are  throwing  off  diph- 
theria toxin.  It  will  be  remembered  also  that  we 
got  the  toxin  to  immunize  the  horse  by  growing  these 
germs  in  a  laboratory  and  then  saving  the  resultant 
toxin.  When  they  grow  in  the  throat  of  a  child, 
they  throw  off  the  toxin  in  the  same  way.  The  child 
absorbs  the  toxin  and  it  makes  him  sick  just  as  it 


Diseases  Amenable  to  Immunization       57 

would  if  it  were  injected  into  him.  If  he  absorbs 
very  much  of  this  toxin,  it  makes  him  very  sick. 
At  this  juncture  if  you  could  destroy  some  of  the 
toxin  that  the  child  is  absorbing,  he  would  not  be 
so  sick.  Just  here  is  where  we  have  use  for  the 
antitoxin  that  was  taken  from  the  immune  horse. 
We  inject  some  of  this  antitoxin  into  the  child;  the 
antitoxin  immediately  overcomes  some  of  the  toxin 
and  the  child  is  better  at  once. 

What  has  been  said  of  diphtheria  antitoxin  applies 
also  to  tetanus  antitoxin.  To  make  the  tetanus  anti- 
toxin, the  tetanus  germs  are  grown  instead  of  the 
diphtheria  genns;  otherwise  the  two  processes  are 
identical. 

Bear  in  mind,  however,  that  when  the  horse  is  im- 
munized against  diphtheria,  he  will  not  produce  any 
kind  of  antitoxin  except  diphtheria  antitoxin;  and  that 
wfien  immunized  against  tetanus,  he  will  produce  only 
tetanus  antitoxin. 

So  much  for  the  production  of  diphtheria  and 
tetanus  antitoxins,  and  how  they  are  used  in  the 
treatment  of  these  diseases.  There  is  also  another  use 
to  which  these  antitoxins  are  put,  however,  and  that 
is  to  immunize  persons  against  diphtheria  or  tetanus 
and  thereby  prevent  the  disease.  When  diphtheria 
occurs  in  a  family,  for  example,  the  child  having 
the  disease  is  given  curative  (large)  doses  of  antitoxin. 
That  disposed  of,  attention  is  then  turned  to  the 
other  children  who  have  been  exposed  to  the  disease. 
The  older  practice  was  to  give  each  one  of  them 
an  immunizing  (small)  dose,  but  lately  that  practice 


58  Forty  Notifiable  Diseases 

is  not  so  common.  It  is  now  known  that  not  all 
children  are  susceptible  to  diphtheria,  and  it  would 
be  useless  and  expensive  to  give  antitoxin  to  those 
not  susceptible  to  the  disease.  There  is  a  test  known 
as  the  Schick  test  by  which  the  doctor  can  tell  which 
children  are  inamune  to  diphtheria.  This  test  is 
applied  and  then  antitoxin  is  given  only  to  those 
who  are  susceptible  to  the  disease. 

Likewise  when  a  person  develops  tetanus,  the 
tetanus  antitoxin  is  given  in  large  doses,  but  when 
one  merely  gets  a  wound  that  is  likely  to  be  infected 
by  tetanus  germs  ^  an  immunizing  (small)  dose  of 
tetanus  antitoxin  is  given  to  prevent  the  disease. 
Immunity  that  is  conferred  by  an  antitoxin  is  called 
passive  immunity,  whereas  that  conferred  by  the 
use  of  attenuated  germs  is  called  active  immunity. 
Passive  immunity  is  not  usually  so  long-lasting  as 
active  immunity.  ^ 

*  "  In  nature  the  tetanus  bacillus  has  been  found  by  Nicolaier 
and  others  to  occur  in  the  superficial  layers  of  the  soil.  The  earth 
of  cultivated  and  manured  fields  seems  to  harbor  this  organism  with 
especial  frequency,  probably  because  of  its  presence  in  the  dejecta 
of  some  domestic  animals."  Hiss  and  Zinsser. 


CHAPTER  FIFTEEN 
Inter-influence  of  Disease 

It  has  long  been  recognized  that  some  diseases 
exert  their  own  direct  influence,  and  also  an  indirect 
influence  through  some  other  disease.  Hookworms, 
for  example,  cause  very  few  deaths,  directly.  In 
1918  there  were  only  29  deaths  from  hookworms 
reported  in  the  Registration  Area  of  the  United 
States.  But  there  is  httle  doubt  that  through  its 
devitalizing  influence  it  does  increase  the  number 
of  deaths  from  other  diseases,  such  as  malaria, 
typhoid,  and  tuberculosis.  Indeed,  from  Kofoid's 
recent  study  of  the  influence  of  hookworms,  it 
now  seems  certain  that  they  were  of  great  im- 
portance in  increasing  the  death  rate  among  the 
soldiers  during  the  World  War,  and  that  they  also 
increased  in  the  training  camps  the  sickness  rate 
from  measles,  laryngitis,  tonsillitis,  bronchitis,  and 
pneumonia. 

While  hookworm  and  a  few  other  diseases  thus 
indirectly  influence  to  some  extent  the  death  rate, 
it  is  the  respiratory  diseases  —  tuberculosis,  pneu- 
monia, and  influenza — ^^that  seem  to  cause  the 
most  trouble  in  this  respect.  In  1917  there  were, 
in  round  numbers,  110,000  deaths  from  tuberculosis 
in  the  Registration  Area,  74,000  from  pneumonia, 
and  12,000  from  "flu."  That  was  an  ordinary  year, 
and  not  characterized  by  any  special  epidemic. 
Influenza  took  its  place  just  above  measles  and 
whooping-cough  in  the  number  of  deaths  that  it 

59 


60  Forty  Notifiable  Diseases 

caused.  But  in  1918  there  was  a  great  epidemic 
of  influenza  that  spread  all  over  the  world.  The 
number  of  deaths  in  the  Registration  Area  mounted 
up  from  12,000  to  232,000!  This  undoubtedly  ex- 
erted a  profound  influence  on  the  other  respiratory 
diseases.  At  any  rate,  tuberculosis  mounted  up  from 
110,000  in  1917  to  121,000  in  1918!  The  increase 
in  pneumonia  was  still  more  pronounced,  the  deaths 
from  that  disease  mounting  up  from  74,000  in  1917 
to  167,000  in  1918! 


CHAPTER  SIXTEEN 
Tuberculosis 

The  books  and  pamphlets  that  have  been  written 
about  tuberculosis  would  fill  a  library,  but  if  you 
were  to  read  such  a  library  through  and  jot  down 
the  really  important  things,  your  notes  would  hardly 
fill  a  page.  They  would  read  about  as  follows: 
Caused  by  germs  known  as  tubercle  bacilli. 
Germs  may  attack  any  part  of  the  body. 
When  they  attack  the  lungs,  the  disease  is  called 

"consumption." 
When  they  attack  glands,  as  in  the  neck,  it  is 

called  "scrofula." 
When  they  attack  the  spinal  column,  it  is  called 

"Pott's  disease." 
When  they  attack  the  hip,  it  is  called  "hip-joint 

disease." 
Abscesses  caused  by  tubercle  bacilli  are  called  "cold 

abscesses." 
Consumption  is  the  commonest  form  of  the  disease. 
Time  contracted :  usually  in  childhood. 
Develops  into  active  cases  chiefly  from  15  to  30 

years  of  age. 
Maximum  number  of  deaths  occur  between  30 

and  39  years  of  age.   After  being  contracted,   it 

lies  dormant  for  a  certain  period,  during  which 

time  no  germs  are  given  off.    At  this  time  the 

disease  is  called  a  "closed  case." 
Whenever  it  develops  and  begins  to  discharge 

germs,  it  is  called  an  "open  case." 

61 


62  Forty  Notifiable  Diseases 

All  cases  are  closed  cases  before  becoming  open. 

Closed  cases  are  not  contagious. 

Many  closed  cases  recover  without  ever  becoming 

open.    Such  recovered  cases  leave  scars  in  the 

lungs.     This   fact   gives   rise    to   the    German 

saying,  "Every  man  has  tuberculosis  before  he 

dies." 
The  disease  is  found  in  all  parts  of  the  world. 
It  causes  more  deaths  than  any  other  one  disease. 
One  form  of  tuberculosis  attacks  cattle. 
A  form  attacks  birds,  as  parrots  and  chickens. 
A  form  attacks  fishes. 
One  form  even  attacks  turtles. 
Tuberculosis  of  cattle  attacks  man. 
Man  spreads  the  germs  by  coughing  them  up  and 

spitting  them  out. 
Cows  do  not  spit,  hence  the  germs  are  not  spread 

in  that  way.    Instead,  they  are  spread  by  being 

swallowed  and  passed  in  the  feces. 
Two  ways  of  preventing  the  disease: 

1.  Prevent  the  spreading  of  germs. 

a.  From  human  beings,  by  hospitalization  of 

the  sick.  Should  be  done  by  state. 

b.  From  cows,  by  testing  all  dairy  cattle  for 

tuberculosis.  Should  be  supervised,  at 
least,  by  state. 

2.  Prevent    closed    cases   from    lighting    up    into 

open  cases.  Should  be  done  by  individual. 
Best  accomplished  by  general  hygienic 
measures  and  above  all  by  keeping  body 
weight  to  approximately  normal. 


CHAPTER  SEVENTEEN 
The  So-called  Madstone 

Of  the  various  superstitions  known  to  the  author 
in  connection  with  any  of  the  diseases  discussed, 
the  most  pronounced  pertain  to  hydrophobia.  One 
superstition  is  that  hydrophobia  is  at  its  worst  in 
dog-days.  Another  is  that  if  a  person  is  bitten  by 
a  dog,  and  the  animal  later  "goes  mad,"  the  person 
will  also  go  mad.  But  the  most  outstanding  of 
these  superstitions  is  that  a  "madstone"  will  cure 
rabies,  and  because  this  superstition  is  so  strongly 
intrenched  in  the  minds  of  many  persons,  it  will  be 
discussed  somewhat  in  detail. 

Though  few  know  what  a  madstone  is,  many 
beheve  in  its  virtues.  Every  httle  while  one  sees 
in  the  press  reports  that  a  hydrophobia  victim  has 
been  taken  somewhere  to  have  a  madstone  appUed. 
Near  Water  Valley,  Mississippi,  is  an  old  gentleman 
who  has  a  madstone  that  I  once  had  the  privilege 
of  holding  in  my  hand.  It  is  about  the  size  and 
shape  of  a  half  walnut,  with  the  split  side  sHghtly 
concaved.  It  is  light  in  weight,  entirely  unUke  a 
stone,  fissured  with  smaU  cracks,  and  of  an  ashen 
color.  With  the  point  of  my  knife,  even  at  the 
risk  of  arousing  my  host's  anxiety,  I  determined 
that  it  was  soft  enough  to  flake  off.  The  story  goes 
that  the  owner's  father  got  it  from  a  deer,  killed 
in  the  swamps  of  Arkansas  many  years  ago.  The 
point  of  the  deer's  heart,  he  said,  rested  in  the  httle 
depression  in  the  flattened  side  of  the  "stone." 

63 


64  Forty  Notifiable  Diseases 

Extolling  its  virtues,  the  old  man  told  me  that 
his  madstone  would  cure  snake  bites  as  well  as  the 
bite  of  a  dog.  He  had  cured  many  snake  bites  with 
it.  Asked  what  kind,  he  said  "chiefly  spreading 
adders."  (It  should  be  noted  in  this  connection  that 
the  "spreading  adder"  or  "hog-nosed  snake"  is  not 
poisonous!)  He  prized  the  madstone  very  highly  — 
had  even  refused  $300  for  it,  he  said.  His  price  for 
applying  it  for  the  bite  of  a  dog  was  $25,  but  now 
that  other  things  had  gone  up  so,  his  price  also  had 
gone  up  to  $35.  He  charged  $5  for  applying  it  to 
a  "spreading  adder"  bite. 

There  is  another  madstone  at  Jackson,  Mississippi, 
of  which  I  have  a  photograph,  furnished  me  by  the 
granddaughter  of  the  owner.  I  have  no  history  of 
this  stone. 

To  determine  how  many  people  beheve  in  a  mad- 
stone, I  have  tested  about  2000  individuals,  and 
find  that  37  per  cent  of  those  tested  would  resort 
to  its  use. 

As  to  what  the  madstone  really  is,  I  could  not 
say  certainly;  but  the  one  that  I  saw  is,  in  my 
opinion,  a  dried  clot  of  blood.  I  fancy  gall-stones 
may  sometimes  function  in  this  reputed  r61e. 

I  have  heard  it  said  that  madstones  are  taken 
from  the  stomachs  of  deer  or  cows,  and  are  in  part 
an  accretion  of  hairs  that  get  into  the  stomach  when 
the  animal  hcks  itself. 


GLOSSARY 

Actinomycosis  (ak-tin-o-my-ko'sis).  From  the  Greek,  cJUin,  a 
"ray,"  6uad  mukos,  a  "fungus.'^'  The  germ  of  the  disease  is  often 
called  the  ray  fungus.  Common  names  of  the  disease:  "big-head" 
and  "lumpy-jaw."  First  observed  in  cattle.  Looks  like  one  or 
several  big  abscesses  about  the  head  or  jaw,  only  these  swellings 
do  not  disappear.  Affects  man  very  much  the  same  way.  Not 
common. 

Anchylostomiasis  (ang-ky-lo-sto-mi'a-sis).  (iSee  Hookworm.) 
Anthrax  (an'thrax).  From  the  Greek,  anth-ax,  meaning  a  "coal" 
or  "boil."  A  disease  of  cattle,  sheep,  goats,  and  other  animals,  but 
occurs  also  in  man.  Other  common  names:  "malignant  pustule" 
and  "wool-sorter's  disease."  When  man  gets  it,  it  is  usually  from 
handhng  wool  or  hides.   Occasionally  got  from  a  shaving  brush. 

Bacillus  (ba-sil'us).  Plural,  bacilli.  A  germ  shaped  like  a  corncob. 
Streplobacillus  (strep'to-ba-sil-us).  A  group  form  of  baciUi  in  which 
the  members  are  arranged  end  to  end  in  a  chain. 

Bacteria.  Singuleir,  baclerium.    {See  Germ.) 

Cancer.  A  disease  of  unknown  origin,  causing  many  deaths,  par- 
ticularly among  people  past  middle  life.  A  cancer  cannot  be  ciured 
but  can  be  removed  when  not  too  large  or  inaccessible,  and  the 
wound  will  heal.  If  all  the  cancer  tissue  is  removed,  the  cancer 
will  not  return;  but  if  the  sUghtest  bit  is  left,  recurrence  is  certain. 
The  best  way  to  remove  cancer  is  by  operation  or  by  the  application 
of  radium,  though  it  is  sometimes  successfully  removed  by  scHcalled 
"cancer  paste"  (the  latter  treatment  is  hazardous,  however).  Some- 
times cancers  are  so  located  that  operation  is  impossible;  in  such 
cases  the  X-ray  or  radium  is  resorted  to.   (See  page  40.) 

Carrier.  (See  page  45.) 

Chancroid.   (See  page  29.) 

Chicken-pox.  The  more  technical  name  is  varicella,  which  is  the 
diminutive  of  variola,  or  smallpox.  A  mild  eruptive  disease  of  chil- 
dren. Very  common.  Not  very  important  in  itself,  causing  few  or 
no  deaths;  but  mild  cases  of  smallpox  are  often  thought  to  be  chicken- 
pox,  and  in  this  way  smallpox  epidemics  get  started.  It  is  therefore 
thought  best  to  require  that  chicken-pox  be  reported  to  the  health 
authorities. 

Cholera  (kol'er-a).  From  the  Greek,  kole,  meaning  "bile."  There 
are  three  forms  of  cholera  to  be  reckoned  with: 

(a)  Cholera  infantum,  also  known  as  summer  complaint.  Attacks 
infants  and  young  children,  causing  severe  abdominal  pains, 
purgation,  vomiting,  fever,  and  great  prostration.  Responsi- 
65 


66  Glossary 

ble  (or  a  great  many  deaths,  although  not  generally  considered 
communicable  and  not  usually  notifiable. 
(6)    Cholera  nostras,  connnonly  known  as  cholera  morbus.    Affects 
adults  very  much  as  cholera  infantum  affects  children.    Not 
communicable  and  not  notifiable,  except  when  Asiatic  cholera 
is  present. 
(c)    Asiatic  cholera.    Always  notiGable.    Common  in  India  and 
other  parts  of  Asia,  where  it  occurs  in  great  epidemics,  often 
causing  hundreds  of  thousands  of  deaths.   There  was  a  great 
epidemic  of  it  in  London  in  1854.    In  Hamburg,  (lermany, 
in  1893  there  was  an  epidemic  that  lasted  two  months,  during 
which  time  there  were  over  17,000  deaths.    Asiatic  cholera 
is  due  to  a  minute  vegetable  organism,   the  spirillum    {see 
page  8)  of  Asiatic  cholera.   The  great  epidemics  of  this  dis- 
ease are  usually  due  to  the  fact  that  the  drinking-water  sup- 
plying large  communities  in  some  way  becomes  contaminated 
with  sewage. 
Hogs  have  cholera,  and  so  do  chickens,  but  these  forms  of  the 
disease  are  entirely  different  from  the  disease  affecting  man.    {See 
page  16.) 

Coccus  (kok'us).  Plural,  cocci.  A  spherical  bacterium.  Diplococcus 
(dip'lo-kok-us).  A  group  form  of  cocci,  arranged  in  twos.  Clonorrhea, 
meningitis,  and  pneumonia  are  cau.sed  by  diplococci  known  as  "gono- 
cocci,"  "meningococci,"  and  "pneummxx^ci,"  respectively.  Staphylo- 
coccus (staf'il-o-kok-us).  A  group  of  germs  that  arrange  them.selves 
in  clusters  like  a  bunch  of  grapes.  Streptococcus  (strep'to-kok-us). 
A  group  of  germs  that  arrange  themselves  in  a  chain,  like  a  string 
of  beads. 

Continued  fever.  Not  a  disease  in  itself.  When  a  doctor  cannot 
tell  whether  a  given  case  Is  typhoid,  or  malaria,  or  something  else, 
and  the  disease  hangs  on  for  7  days,  it  is  reported  as  "continued 
fever." 

Dengue  (den'gay).  Also  called  "break-bone  fever."  Patients 
describe  the  symptoms  as  feeling  "as  if  every  bone  in  the  Ixxly  were 
breaking."  In  the  Southern  states  it  occasionally  occurs  in  epidemics. 
Persons  rarely  —  perhaps  never  —  die  from  it.  In  fornjer  times  when 
yellow  fever  used  to  break  out  every  few  years,  and  the  fear  of  it 
was  hanging  over  the  South,  an  outbreak  of  dengue  was  looked  upon 
with  very  great  suspicion  lest  it  should  prove  to  l)e  yellow  fever. 
It  is  now  agreed  that  dengue  is  transmitted  by  mosquitoes,  and 
by  the  same  kind  of  mosquito  that  transmits  yellow  fever,  the  species 
knf>wn  as  /Edes  calopus. 

Diphtheria  (dif-the'ri-a).  From  the  Greek,  diphthera,  "skin"  or 
"membrane."    An  acute  disease,  very  contagious.    Formerly  called 


Glossary  67 

in  some  sections  "choking  complaint,"  because  of  tlie  severity  of 
tlie  throat  symptoms.   Caused  by  little  rod-like  germs  in  the  throat. 
(See  page  45.) 
Dysentery  (dis'-en-ter-e).  There  are  two  kinds  of  dysentery: 

(a)  Amebic  dysenlery.  Caused  by  very  minute  animal  organisms 
in  the  intestines.  This  kind  is  chronic,  sometimes  lasting  for 
years;  persons  who  have  it  are  liable  to  develop  abscess  of 
the  liver.   {See  page  16.) 

(6)    Bacillary  dysenlery.    Caused  by  a  bacillus  in  the  intestines. 

Encephalitis  (en-sef-a-li'tis).  From  the  Greek,  kephale,  "head," 
combined  with  His,  which  means  an  inflammation.  A  febrile  disease 
(that  is,  involving  a  fever),  the  locus  of  which  is  the  brain.  Causes 
a  variety  of  nervous  symptoms,  such  as  prolonged  sleep  or  drowsiness, 
excessive  talking  or  laughing.       ' 

Epidemiology  (ep-i-dem-i-ol'o-gy).  A  knowledge  made  up  of  all 
the  facts  that  deal  with  epidemics.  The  spread  of  communicable 
disease  is  conditioned  by  many  and  varied  factors.  A  milk-borne 
epidemic  of  typhoid  fever,  for  instance,  would  follow  the  milk  route 
of  the  offending  dairy,  while  a  water-borne  outbreak  would  be  dis- 
tributed wherever  the  infected  water  was  used.  Malaria,  on  the 
other  hand,  being  mosquito-borne,  would  have  an  entirely  different 
set  of  limiting  factors,  hookworms  would  have  still  another,  smallpox 
another,  and  so  on.    Epidemiology  has  to  do  with  all  these  factors. 

Favus.  From  the  Latin,  favus,  "honeycomb."  One  of  the  "ring- 
worms." Forms  crisp,  yellowish,  cup-like  crusts  on  the  scalp.  Rare 
in  this  country,  but  more  common  among  certain  classes  in  Europe. 
Of  enough  seriousness  to  bring  it  within  the  notifiable  class,  and 
when  found  among  immigrants  it  is  cause  for  exclusion. 

There  are  several  other  forms  of  ringworm,  which  although  not 
notifiable  are  common  and  of  more  consequence  than  is  generally 
supposed. 

German  measles.  Also  called  rubeola  and  roseola.  A  mild  eruptive 
disease,  bearing  about  the  same  relation  to  measles  that  chicken-pox 
does  to  smallpox. 

Germ.  (See  page  3.)  The  quotations  from  Hill,  below,  sum  up 
three  of  the  more  important  facts  concerning  germs: 

"Germs  of  all  kinds  are  simply  tiny  plants  (or  animals);  some 
spherical,  some  more  or  less  sausage-shaped.  .  .  . 

"Germs  of  any  kind  never  'evolve'  from  dirt.  They,  like  other 
plants  (or  animals),  come  only  from  predecessors.  .  .  . 

"Many  different  kinds  of  germs  that  do  not  produce  disease 
flourish  on  or  in  our  skins,  noses,  mouths,  and  intestines  all  the  time." 


68  Glossary 

Glanders.  A  very  contagious  disease  of  horses  and  particularly 
of  mules,  in  which  it  is  usually  acute  and  rapidly  fatal.  It  is  com- 
municable to  man.  When  a  case  of  glanders  occurs  at  any  place 
in  the  state,  the  matter  is  at  once  reported  to  the  Live  Stock  Sanitary 
Commission  of  that  state;  or  if  the  state  has  no  commission,  it  is 
reported  to  the  State  Board  of  Health  and  to  the  Bureau  of  Animal 
Industry  in  Washington.  Steps  are  at  once  taken  to  stamp  it  out. 
In  1907  an  outbreak  occurred  in  Cook's  Stables,  Jacksonville, 
Florida.  Some  80  horses  and  mules  were  found  to  have  the  disease. 
They  were  taken  out  to  the  woods,  a  great  trench  dug,  and  the 
animals  were  killed  and  piled  in  the  trench,  covered  with  lime,  and 
buried.  For  those  who  want  to  know  the  rest  of  the  story,  it  might 
be  added  that  when  the  next  session  of  the  Florida  legislature  met, 
Mr.  Cook  had  a  bill  introduced  through  which  he  hoped  to  obtain 
payment  for  the  loss  of  the  animals.  His  argument  was  that  he  had 
killed  them  to  keep  the  disease  from  spreading,  and  in  that  way 
had  protected  the  rest  of  the  state.  The  counter  argument  was  that 
the  horses  were  sick  and  dying,  and  were  of  no  value,  hence  the 
state  should  not  reimburse  him,  even  in  part.  This  incident  illus- 
trates the  seriousness  of  an  epidemic  of  glanders  when  once  it  get« 
started. 

Hookworm  disease.  Caused  by  small  worms  (the  so-called  "hook- 
worms") in  the  intestine.  Several  animals  also  have  hookworms, 
as  the  dog  and  the  cat;  but  these  hookworms  are  not  all  alike,  each 
kind  of  animal  having  its  own  kind  of  hookworm.  Man  has  two 
kinds,  known  respectively  as  the  Old  World  hooktvorms  and  the  New 
World  hooktporms,  or  the  European  and  the  American.    (See  page  38.) 

The  hookworms  of  man  inhabit  a  zone  that  belts  the  earth  between 
an  irregular  line  at  about  40  degrees  North  latitude  and  a  similar 
line  about  40  degrees  South  latitude.  Persons  living  in  this  zone 
are  more  or   less  liable  to  get  the  infection. 

Tfiere  can  be  no  spread  of  hookworm  disease  except  through  soil 
pollulion.   {See  page  16.) 

Immunity.  When  a  person  is  spoken  of  as  being  immune  against 
a  disease,  it  means  that  he  will  not  take  it  however  much  he  may 
be  exposed.  For  example,  when  a  person  is  vaccinated  against  small- 
pox he  becomes  immune  against  that  disease  and  will  not  take  it. 
There  are  certain  diseases,  however,  to  which  man  is  not  susceptible. 
Chicken  cholera  is  one  of  these.  Man's  relation  to  such  diseases 
is  spoken  of  as  natural  immunity.  When  one  is  immunized  against 
a  disease  by  vaccination,  or  by  having  the  disease,  that  condition 
is  called  acquired  immunity. 

Incubation  period.  That  period  of  time  between  the  exposure  to 
a  disease  and  the  onset. 


Glossary  69 


Influenza.  One  of  the  acute  infectious  diseases  which  in  a  most 
malignant  form  assumed  world-wide  proportions  during  the  World 
War.  The  very  high  death  rate  was  due  to  the  large  proportion 
of  cases  that  developed  pneumonia. 

Leprosy.  The  points  to  remember  about  leprosy  are  that  it  is 
caused  by  "germs,"  which  are  known  as  the  lepra  bacilli;  that  it 
is  accordingly  contagious,  but  so  mildly  so  that  people  may  some- 
times live  with  it  for  years  without  ever  contracting  it;  that  it  is 
not  hereditary;  that  it  is  not  white,  as  many  suppose;  that  it  is  a 
slow  chronic  disease,  often  lasting  15  or  20  years;  and  that  there 
are  some  200,000  cases  in  the  world.  Most  of  these  cases  are  in 
the  Far  East  —  about  half  of  them  in  India  and  China.  There 
are  five  or  six  thousand  cases  in  the  Philippines.  In  1909  there 
was  an  International  Leper  Congress  held  at  Bergen,  Norway.  At 
that  time  135  cases  were  reported  from  the  United  States.  These 
were  distributed  in  various  centers,  the  largest  of  which  was  in 
Louisiana.  There  were  some  40  cases  in  this  center.  Other  centers 
were  at  Key  West,  Florida,  and  in  Minnesota,  California,  and 
Massachusetts;  the  rest  were  distributed  here  and  there  over  the 
country.  The  United  States  has  lately  taken  over  the  leper  sana- 
torium in  Louisiana,  so  that  lepers  from  any  part  of  the  United 
States  may  now  be  taken  care  of  there. 

An  interesting  light  on  the  disease  comes  from  Hawaii.  There 
are  two  schools  in  Honolulu  for  the  non-leprous  children  bom  of 
leprous  parents.  All  the  lepers  in  Hawaii  are  sent  to  the  Isleuid 
of  Molokai,  where  there  is  quite  a  large  and  happy  colony  of  them. 
Whenever  a  child  is  born  there  of  leprous  parents,  it  is  inunediately 
taken  back  to  Honolulu  and  put  in  one  of  these  schools  for  such 
children.  There  are  about  40  boys  in  one  school  and  about  as  many 
girls  in  the  other,  and  yet  not  one  of  these  children  has  ever  devel- 
oped leprosy. 

Malaria.  The  outstanding  facts  about  malaria  are: 

(a)    It  is  transmitted  by  mosquitoes  and  in  that  way  only.  People 

do  not  get  it  from  swamps  or  from  night  air,  or  from  eating 

muscadines,  or  late  watermelons,  or  from  eating  anything 

else  —  it  is  got  from  mosquitoes  only. 
(6)    Mosquitoes  likewise  do  not  get  it  from  swamps,  or  night  air, 

or  from  eating  muscadines  or  late  watermelons  —  they  get  it 

from  man,  and  from  man  only. 

(c)  Only  certain  kinds  of  mosquitoes  can  transmit  it  —  those 
known  as  Anopheles. 

(d)  An  Anopheles  cannot  transmit  it  until  he  bites  some  person 
who  has  it  —  gets  "loaded,"  so  to  speak.  A  loaded  Anopheles 
can  give  malaria;  one  that  is  not  loaded  cannot. 


70  Glossary 


(e)  The  protection  of  the  patient  from  the  bile  of  Anopheles  during 
the  whole  term  that  fie  is  a  carrier  also  protects  the  public  round 
about  him. 

(/)    Chills  and  fever  may  usually  be  taken  to  be  malaria. 

(flf)  A  person  having  had  malaria  for  some  time  may  still  carry 
in  his  blood  the  germs  of  malaria  after  the  chills  and  fever 
have  stopped.  In  that  case  he  is  called  a  "malaria  carrier." 
Although  he  himself  is  well,  or  relatively  so,  if  a  mosquito  of  the 
right  kind  bites  him  the  mosquito  will  get  the  germs  and  then 
pass  them  on  to  some  one  else.  It  is  important,  therefore, 
to  treat  malaria  or  "chills  and  fever"  very  vigorously,  and 
to  get  the  patient  well  as  soon  as  possible  so  that  he  will 
not  become  a  carrier. 

(/j)  It  is  not  the  cause  of  every  obscure  ache  and  pain  that  human 
flesh  is  heir  to. 

(0  Quinine  is  the  basis  of  all  malaria  treatment.  As  the  late 
Dr.  Eugene  Foster  used  to  say,  in  the  treatment  of  malaria 
use  quinine  "internally,  externally,  and  eternally." 

Measles.  One  of  the  eruptive  fevers.  Causes  relatively  few  deaths 
in  itself,  but  during  the  disease  pneumonia  not  infrequently  develops 
and  ends  disastrously.  "Big"  measles  and  "little"  nteasles  mean 
the  same  thing.  "Black"  measles  is  also  the  same  disease  but  in 
a  very  aggravated  form.  The  black  feature  is  due  to  the  rupture 
of  small  blood  vessels  and  consequent  bleeding  under  the  skin.  This 
may  also  occur  in  other  diseases,  as  smallpox,  scarlet  fever,  and 
meningitis.  There  was  a  terrible  outbreak  of  disease  in  London  in 
1666,  known  as  the  "Black  Plague."  It  was  probably  one  of  these 
diseases  just  mentioned  —  possibly  smallpox. 

Meningitis  (men-in-ji'tis).  Also  known  as  "cerebrospinal  fever" 
or  "spotted  fever."  Occurs  in  epidemics,  whi»;h  are  more  or  less 
local.  Regarded  as  contagious.  Called  spotted  fever  l)e(!ause  some 
of  the  cases  have  hemorrhages  under  the  skin,  making  dark  spoUs. 
After  a  person  gets  over  a  severe  case,  he  is  still  likely  to  have  some 
of  its  effects.  Patients  are  often  left  cripples.  One  young  man  of 
the  author's  acquaintance  was  left  cross-eyed. 

Microbe.   Another  name  for  germ.   {See  Germ;  also  page  3.) 

Mumps.  An  acute  disease  of  the  parotid  and  salivary  glands, 
which  swell  and  become  extremely  painful.  The  disease  does  not 
last  very  long  —  3  or  4  days  to  a  week.  It  sometimes  affects  the 
generative  organs  of  both  male  and  female;  in  that  case  it  is  a  dan- 
gerous malady. 

Paratyphoid.  Much  like  typhoid  fever;  the  difference  is  more 
in  the  germ  than  in  the  disease.    {See  page  16). 


Glossary  71 

Plague,  or  bubonic  plague.  Essentially  a  disease  of  rodents  (rats, 
squirrels,  and  related  animals).  Transmitted  from  rat  to  rat  and 
from  rat  to  men  by  fleas.  The  disease  has  long  prevailed  in  the 
Orient,  particularly  in  India.  It  has  appeared  in  the  United  States 
only  a  few  times.  About  1903  or  1904  it  was  introduced  into  Cali- 
fornia, and  since  then  has  appeared  twice  in  New  Orleans  and  other 
Gulf  ports.  A  vigorous  campaign  of  rat-killing  has  eradicated  the 
disease  each  time  it  has  appeared  in  this  country,  although  it  is 
said  still  to  exist  among  California  ground  squirrels. 

An  outstanding  feature  of  plague  is  its  method  of  traveling  from 
country  to  country.  It  seems  to  be  carried  exclusively  by  the  Nor- 
way rat,  which,  by  the  way,  is  a  great  traveler,  by  boat  and  by 
rail.  If  plague-infected  rats  go  aboard  a  boat  and  other  rats  on 
the  ship  get  infected,  the  disease  may  develop  at  sea.  Then  at  any 
port  where  the  boat  touches,  the  rats  may  disembark  and  introduce 
the  disease. 

Pneumonia.  Aside  from  tuberculosis,  this  disease  causes  more 
deaths  than  any  other  in  this  country.  The  death  rate  from  pneu- 
monia is  generally  higher  in  the  colder  latitudes  than  in  the  warmer. 
The  fever  runs  high,  and  the  breathing  is  very  rapid.  In  about  5 
to  8  days  from  the  onset  there  occurs  what  is  called  the  "crisis." 
The  patient  breaks  out  in  a  profuse  sweat,  the  temperature  falls 
rapidly  to  normal  or  below,  and  the  patient  goes  into  a  state  of 
collapse.  It  is  at  this  juncture  that  most  deaths  occur.  If  the  patient 
can  get  through  the  crisis  all  right,  he  will  probably  recover.  One 
student,  when  asked  what  pneumonia  was,  replied:  "A  kind  of  cold 
in  the  lungs."  The  description  is  good. 

Poliomyelitis  (pol-e-o-mi-e-li'tis).  From  the  Greek  words  polios, 
"gray,"  and  muelos,  "marrow";  combined  with  itis,  meaning  an 
inflammation;  literaUy,  "inflammation  of  gray  matter."  Commonly 
caUed  infantile  paralysis.  This  disease  is  very  insidious.  The  child 
complains  of  not  feeling  well  —  perhaps  does  not  eat  any  breeikfast, 
and  is  disinclined  to  play.  In  a  day  or  two  it  is  noticed  that  he  is 
partly  paralyzed  in  one  or  more  limbs.  As  the  paralysis  is  caused 
by  the  destruction  of  the  nerves  in  the  spinal  cord  that  lead  to  the 
muscles,  there  is  little  that  can  be  done  for  it. 

Rabies,  or  hydrophobia.  Transmitted  through  the  bite  of  an 
animal  infected  with  rabies.  Once  developed,  the  disease  is  always 
fatal.  It  is  usually  about  4  weeks  —  sometimes  more,  sometimes 
less  —  from  the  time  the  person  is  bitten  until  he  develops  the 
disease.  If  during  this  time  he  takes  the  Pasteur  treatment  (the 
only  effective  method  of  vaccinating  against  rabies),  he  wiU  not  be 
likely  to  develop  rabies.  But  it  takes  3  to  4  weeks  to  give  the  Pasteur 
treatment;  so  there  is  no  time  to  be  lost.    If  you  are  bitten  by  an 


72  Glossary 

animal  and  are  not  sure  whether  it  is  rabid  or  not,  the  thing  to  do 
is  to  begin  the  Pasteur  treatment  at  once  —  do  not  wail.  Then,  shut 
up  the  animal  to  keep  him  from  biting  any  one  else,  or  other  animals, 
and  watch  him  for  further  symptoms  of  rabies.  If  he  has  the  disease, 
he  will  die  in  3  or  4  days.  If  he  does  not  die  in  a  week,  you  will 
know  that  it  is  not  rabies,  and  you  can  drop  the  treatment.  Above 
all  things  do  not  kill  the  dog.  You  can  be  much  more  certain  by 
watching  him  than  by  sending  his  head  to  the  laboratory.  If  you 
do  kill  the  dog,  you  will  have  to  complete  the  Pasteur  treatment 
regardless  of  what  the  laboratory  finds.  If  you  do  not  kill  the  dog, 
you  may  be  able  to  drop  the  treatment  in  a  week  or  so. 
Rocky  Mountain  spotted  fever.    (See  pages  28  and  39.) 

Scarlet  fever.  (Scarlalina  is  only  another  name  fw  the  same 
disease.)  One  of  the  eruptive  fevers.  Characterized  by  sore  throat 
and  a  scarlet  rash.  In  later  stages  of  the  disease  the  epidermis 
(outer  skin)  sheds  off  more  or  less.  In  some  cases  the  hands  pee! 
oflF  almost  like  taking  off  a  glove.  In  mild  cases  there  is  not  much 
of  this  shedding,  or  "desquamation"  as  it  is  called  in  books. 

Scarlet  fever  sometimes  injures  the  hearing.  There  is  a  little  tube 
running  from  the  throat  to  the  ear  that  enables  air  to  get  to  the 
middle  ear.  It  is  called  the  Eustachian  tube.  When  it  becomes 
inflamed,  as  it  often  does  in  scarlet  fever,  it  may  "grow  together," 
ao  that  air  cannot  pass  through  it.  Inflammation  of  the  middle 
ear  is  a  common  complication;  in  that  case  hearing  may  be  per- 
manently damaged. 

Septicemia.  In  typhoid,  child-bed  fever,  and  some  other  condi- 
tions, the  germs  causing  the  disturbance  exist  and  multiply  in  the 
blood  stream.   Such  conditions  are  spoken  of  as  "septicemia." 

Smallpox.  A  disease  that  has  always  been  looked  on  with  great 
dread.  Formerly  a  most  terrible  scourge,  but  now  compeiratively 
unimportant.  Sometimes  today  a  case  is  fatal,  but  not  often.  Can 
be  prevented  by  vaccination.  It  is  customtiry  to  make  some  attempt 
to  quarantine  it,  but  as  a  general  rule  that  does  little,  if  any,  good. 
Only  about  one  out  of  every  four  cases  is  ever  reported  to  the  health 
officer.  It  is  perfectly  obvious  that  to  quarantine  one  case  and 
leave  three  at  large  will  do  very  little  good  in  checking  its  spread. 
Every  one  who  wants  to  keep  from  having  smallpox  .should  be 
vaccinated  against  it  and  keep  on  getting  vaccinated  until  it  "takes." 
If  it  does  not  "take,"  it  does  not  show  that  you  are  immune  against 
the  disease  —  it  more  probably  shows  that  the  vaccine  was  dead. 
And  it  is  not  true  that  people  sometimes  have  to  have  the  arm 
taken  off"  because  of  vaccination  — that  never  happens.  {See  page  53.) 

Tetantis,  or  lockjaw.  A  disease  that  is  caused  by  the  germ  of 
tetanus.    The  germ  gets  into  a  wound,  particularly  the  deep  or 


Glossary  73 


"puncture"  wounds,  and  the  poison  that  comes  from  their  growth 
acts  on  the  nervous  system,  causing  the  muscles  to  contract;  hence 
the  jaws  seem  locked.  The  tetanus  germ  is  particularly  prevalent 
about  stables.  Puncture  wounds  received  about  barns  should  be 
promptly  attended  to. 

Lockjaw  can  be  prevented  by  the  use  of  tetanus  antitoxin,  which 
is  in  the  market.  All  persons  who  get  suspicious  wounds  will  be 
safe  if  they  take  an  injection  of  this  germ,  which  is  called  "anti- 
tetanic  serum."  Gunpowder  wounds  are  particularly  dangerous 
sources  of  tetanus.   (See  page  58.) 

Trachoma.  A  disease  of  the  eyelids.  Often  called  "granulated 
lids,"  but  there  are  many  cases  of  "granulated  lids"  that  are  not 
trachoma.  True  trachoma  is  such  a  serious  disease  that  persona 
who  have  it  are  not  permitted  to  come  to  this  country  as  immigrants. 
At  Ellis  Island,  where  most  of  the  immigrants  land,  all  are  examined 
and  those  found  to  have  trachoma  are  sent  back.  There  are  some 
cases  in  this  country,  however.  It  is  fairly  amenable  to  treatment 
by  operative  procedure. 

Trichinosis  (trich-i-no'is).  Most  commonly  a  disease  of  hogs  and 
rats.  Very  rare  among  human  beings  in  the  United  States.  A  tiny 
worm,  the  Irichinella  spiralis,  causes  the  disease.  There  are  thou- 
sands of  them  coiled  up  in  the  muscles  of  a  single  infected  animal. 
It  is  this  that  causes  "measly  pork."  When  a  person  eats  such 
pork  without  sufficient  cooking  to  kill  the  worms,  he  gets  the  disease 
himself.  In  man  it  is  somewhat  like  rheumatism  in  its  effects. 
At  the  packing  houses  all  pork  is  examined  for  these  little  worms, 
and  whenever  found,  the  carcass  is  condemned. 

This  is  another  disease  in  which  the  rat  is  often  involved.  Rats 
eat  scraps  of  meat  and  get  the  infection.  Pigs  may  eat  rats,  and 
man  eats  the  pigs.   The  disease  is  more  interesting  than  important. 

Tuberculosis.   {See  page  61.) 

Typhoid  fever.  A  long-drawn-out  fever  lasting  usually  from  3  to  6 
weeks.  Caused  by  a  vegetable  germ,  the  typhoid  bacillus.  These 
germs  are  passed  from  the  body  of  the  patient  by  millions,  in  the 
saliva,  in  the  urine,  and  in  the  stools.  Consequently  all  sewage  is 
to  be  regarded  as  typhoid  infected.  And  if  through  any  means  it 
contaminates  the  drinking-water,  persons  drinking  this  water  will 
have  typhoid  fever.  This  may  happen  when  a  surface  privy  is  close 
to  a  well.  The  sewage  from  the  privy  seeps  down  when  it  rains, 
and  gets  into  the  well.  Or  it  may  happen  from  emptying  sewage 
into  a  river  and  taking  water  from  the  river  for  domestic  use.  All 
such  water  should  be  filtered  by  the  city.  Typhoid  is  often  spread 
when  flies  have  access  to  open  privies.  They  go  there  to  feed,  get 
the  germs  on  their  feet,  and  then  come  into  the  dining  room  and 
walk  over  the  food. 


74  Glossary 

Sometimes  a  person  may  get  well  from  typhoid  and  still  give  olT 
the  germs  for  weeks  or  months,  or  even  years.  Such  persons  are 
called  "typhoid  carriers."  If  a  typhoid  carrier  works  in  a  dairy 
or  as  a  cook,  or  otherwise  handles  food,  there  is  danger  of  spreading 
the  disease.  It  is  customary  now  to  examine  all  milkers  in  large 
dairies  to  make  sure  that  they  are  not  typhoid  carriers.  Many 
epidemics  of  typhoid  have  been  caused  by  carriers. 

It  is  possible  now  to  be  effectively  vaccinated  against  typhoid. 
{See  page  49.) 

Typhus.  Also  known  as  "jail  fever."  Transmitted  by  both  head 
and  body  lice.  Caused  many  deaths  during  the  recent  war.  Not 
common  in  the  United  States.  Caused  only  16  deaths  here  during 
tlie  year  1917.  Every  precaution  is  taken  at  Ellis  Island  and  other 
immigration  stations  to  prevent  its  accidental  introduction. 

Venereal  diseases.  There  are  three  venereal  diseases:  syphilLi, 
gonorrhea,  chancroid.  All  are  contracted  by  sexual  contact.  These 
diseases  are  the  most  terrible  of  all  diseases,  causing  a  great  deal 
of  suffering  —  insanity,  blindness,  disabilities,  and  deaths  —  both 
directly  and  indirectly. 

It  should  be  clearly  understood  that  no  one  who  lives  a  clean  sexual 
life  is  in  danger  from  these  diseases. 

On  page  30  there  is  a  table  listing  llu;  most  salient  features  of 
the  venereal  diseases;  if  you  wish  to  know  more  about  them,  ask 
your  family  physician  —  he  will  be  glad  to  tell  you  all  about  them. 

Whooping-cough.  A  widely  known  disease,  and  much  more  serious 
than  generally  considered.  In  1917,  for  example,  in  the  list  of 
communicable  diseases  it  stood  eighth  as  a  cause  of  deaths.  It  caused 
more  deaths  that  year  than  scarlet  fever,  malaria,  smallpox,  hook- 
worms, and  hydrophobia  combined.  It  is  particularly  fatal  among 
infants  and  very  young  children.  It  should  never  be  considered 
lightly.  And  above  all,  children  should  not  be  exposed  to  it  to  "gel 
it  over.^* 

Yellow  fever.  A  disease  that  is  now  of  more  historic  than  practical 
interest.  It  used  to  prevail  in  Cuba  constantly,  and  every  ywtr  or 
so  it  was  intro<luced  into  the  Unitetl  States.  All  sorts  of  theories 
were  proposed  as  to  how  it  spread.  Hut  in  1900  a  commission  headed 
by  Walter  Re<!d  of  the  United  St^jtes  Army,  working  in  Cuba, 
prov«Ml  that  it  was  transmitted  by  mosquitoes,  of  the  genus  then 
known  as  Culex  fascialus,  but  which  is  now  known  as  jEdes  calopus. 


2053 


3 


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